feat: add multi-language support for 20 locales

Add complete i18n infrastructure with 21 supported languages:
English, Simplified Chinese, Traditional Chinese, Japanese, Korean,
Spanish, French, Italian, Brazilian Portuguese, German, Dutch, Swedish,
Russian, Polish, Ukrainian, Arabic (RTL), Turkish, Hindi, Vietnamese,
Indonesian, and Thai.

- I18nProvider context with three-tier locale detection
  (user preference > navigator.languages > instance default > English)
- ~1500 translation keys per locale with TypeScript-enforced completeness
- Dynamic code-splitting: only the active locale is loaded at runtime
- Language selectors in footer, login page, settings, and mobile sidebar
- Arabic RTL support with CSS logical properties across all components
- Tool names, descriptions, and categories translated via i18n helpers
- Public API endpoint GET /api/v1/config/locale for instance default
- Multi-script font stack (CJK, Arabic, Devanagari, Thai, Cyrillic)
- format() and plural() helpers for interpolation and pluralization
- API error translation mapping (translateApiError)
- 36 Playwright e2e tests verifying all 21 locales load correctly
- 25 unit tests for format, plural, locale detection, and completeness
- Updated translations.md docs and CLAUDE.md conventions

CLAUDE.md

@@ -0,0 +1,162 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## What Is SnapOtter
+
+Open-source, self-hostable image manipulation suite (51 tools). Single Docker container, no external services. Dual-licensed AGPLv3 / commercial.
+
+## Monorepo Layout
+
+```
+apps/web/         # Main React SPA (port 1349)
+apps/api/         # Fastify API server (port 13490)
+apps/landing/     # Marketing site (Vite + React, deployed to Cloudflare Pages)
+apps/docs/        # VitePress documentation site (deployed to Cloudflare Pages)
+packages/shared/  # Constants, types, i18n, permissions -- consumed by all apps
+packages/image-engine/  # Sharp-based image processing pipeline
+packages/ai/      # Python sidecar bridge for ML models
+```
+
+## Tech Stack
+
+| Layer | Technology |
+|-------|-----------|
+| Frontend | React 19, Vite 6, Tailwind CSS 4, Zustand, react-router-dom v7 |
+| Backend | Fastify 5, tsx (no compile step in dev), Sharp |
+| Database | SQLite via Drizzle ORM (better-sqlite3) |
+| AI/ML | Python sidecar (rembg, RealESRGAN, PaddleOCR, MediaPipe, LaMa) |
+| Docs | VitePress |
+| Testing | Vitest (unit/integration), Playwright (e2e) |
+| CI/CD | GitHub Actions, semantic-release, Docker multi-arch |
+| Linting | Biome (format + lint in one pass) |
+
+## Commands
+
+```bash
+pnpm dev                  # Start all dev servers (web on :1349, api on :13490)
+pnpm build                # Build all workspaces (turbo, packages first)
+pnpm typecheck            # TypeScript check across monorepo
+pnpm lint                 # Biome lint + format check
+pnpm lint:fix             # Biome auto-fix
+pnpm test                 # All Vitest tests (unit + integration)
+pnpm test:unit            # Unit tests only
+pnpm test:integration     # Integration tests only (full API)
+pnpm test:e2e             # Playwright e2e tests (main app)
+pnpm test:e2e:landing     # Playwright e2e tests (landing site)
+pnpm test:e2e:docs        # Playwright e2e tests (docs site)
+pnpm test:coverage        # Tests with V8 coverage report
+
+# Run a single test file
+pnpm vitest run tests/unit/my-test.test.ts
+pnpm vitest run tests/integration/my-test.test.ts
+
+# Run a single e2e spec
+pnpm playwright test tests/e2e/my-test.spec.ts
+
+# Database migrations (run from apps/api/)
+cd apps/api && npx drizzle-kit generate   # Generate from schema changes
+cd apps/api && npx drizzle-kit migrate    # Apply pending migrations
+```
+
+## Key Conventions
+
+- **Simplicity over complexity** -- do not over-engineer
+- **Double quotes**, **semicolons**, **2-space indent** (enforced by Biome)
+- **ES modules** in all workspaces (`"type": "module"`)
+- Conventional commits for semantic-release (`feat:`, `fix:`, `refactor:`, `docs:`, `test:`, `chore:`)
+- Zod for all API input validation
+- i18n strings in `packages/shared/src/i18n/en.ts` (reference locale, ~1500 keys)
+- All user-facing strings use `useTranslation()` hook from `apps/web/src/contexts/i18n-context.tsx`
+- Use `t.section.key` for string references, `format(t.key, { var })` for interpolation, `plural(n, one, other)` for pluralization
+- Tailwind uses logical properties for RTL support (`ms-` not `ml-`, `text-start` not `text-left`)
+- 21 supported languages. Adding a new locale: create `packages/shared/src/i18n/<code>.ts` typed as `TranslationKeys`, add to `SUPPORTED_LOCALES` in `index.ts`
+
+## Architecture: How a Tool Works
+
+A "tool" is defined in three places that share the same `toolId` string:
+
+1. **Shared metadata** (`packages/shared/src/constants.ts`) -- `TOOLS[]` array with id, name, description, category, icon, route. Single source of truth for tool metadata consumed by both frontend and backend.
+
+2. **API route** (`apps/api/src/routes/tools/<toolId>.ts`) -- Processing logic. Most tools use the `createToolRoute` factory (`apps/api/src/routes/tool-factory.ts`), which handles multipart parsing, file validation, format decoding (HEIC/RAW/PSD), SVG sanitization, EXIF auto-orientation, Zod settings validation, output saving, preview generation, file versioning, and analytics. A simple tool is ~30 lines: a Zod schema + a process function that calls `@snapotter/image-engine`. Routes are registered in `apps/api/src/routes/tools/index.ts`.
+
+3. **Frontend settings** (`apps/web/src/components/tools/<toolId>-settings.tsx`) -- UI component for the tool's settings panel. Registered in `apps/web/src/lib/tool-registry.tsx` with a `displayMode` (side-by-side, before-after, live-preview, interactive-crop, interactive-eraser, no-dropzone, custom-results).
+
+### Adding a New Tool
+
+1. Add tool definition to `TOOLS[]` in `packages/shared/src/constants.ts`
+2. Create `apps/api/src/routes/tools/<toolId>.ts` -- export a `register<Tool>(app)` function that calls `createToolRoute(app, { toolId, settingsSchema, process })`
+3. Add to the registration array in `apps/api/src/routes/tools/index.ts`
+4. Create `apps/web/src/components/tools/<toolId>-settings.tsx`
+5. Add lazy import + registry entry in `apps/web/src/lib/tool-registry.tsx`
+6. Add i18n strings in `packages/shared/src/i18n/en.ts`
+
+### Request Lifecycle
+
+**Standard tools**: Frontend sends `POST /api/v1/tools/:toolId` (multipart with file + JSON settings) via XHR with upload progress. The `createToolRoute` factory processes and returns `{jobId, downloadUrl, originalSize, processedSize}`.
+
+**AI tools**: Do NOT use `createToolRoute` for their HTTP route. They return `202 Accepted` immediately, process asynchronously via the Python sidecar, and stream progress via SSE (`EventSource` on `/api/v1/jobs/:jobId/progress`). They still register a sync wrapper via `registerToolProcessFn()` for pipeline/batch reuse.
+
+### Pipeline System
+
+Pipelines chain tools: each step's output buffer feeds the next step's input. The tool registry (`toolRegistry` Map) enables pipelines and batch processing to call any registered tool's process function without duplicating logic. CRUD stored in `pipelines` DB table as JSON. Batch processing uses `p-queue` concurrency and returns a ZIP via `archiver`.
+
+## AI Sidecar (packages/ai/)
+
+Two-tier Python execution:
+
+1. **Persistent dispatcher** (primary): Long-lived Python process (`packages/ai/python/dispatcher.py`) communicating via JSON over stdio. Node sends `{id, script, args}` on stdin, Python responds `{id, stdout, exitCode}` on stdout. Progress events stream on stderr as `{progress, stage}`. Pre-imports heavy ML libraries at startup to eliminate cold-start latency. Auto-restarts after 50 requests to prevent memory leaks.
+
+2. **Per-request fallback**: Fresh Python process per request if dispatcher is unavailable. Exponential backoff with crash recovery (5 crashes in 60s = permanent disable).
+
+AI tools require model bundles defined in `packages/shared/src/features.ts` (`FEATURE_BUNDLES`). The API checks `isToolInstalled()` before processing; the frontend shows an install prompt if not installed.
+
+## Image Engine (packages/image-engine/)
+
+`processImage(input, operations[], outputFormat?)` pipes a buffer through named operations. Each operation is a pure function `(Sharp, options) => Promise<Sharp>`. The `OPERATION_MAP` in `engine.ts` dispatches by string key. Individual operations are also exported for direct use by API routes.
+
+## Auth and Permissions
+
+Session-based auth with scrypt password hashing. Three built-in roles (`admin`, `editor`, `user`) with 16 granular permissions defined in `packages/shared/src/permissions.ts`. Custom roles stored in `roles` table. API keys (prefixed `si_`) carry optional scoped permissions that intersect with user role permissions. Auth can be disabled entirely (synthetic anonymous user with `user` role).
+
+## Frontend State
+
+14 Zustand stores in `apps/web/src/stores/`. The central one is `file-store.ts` managing `FileEntry[]` with blob URLs, processing status, and batch ZIP. Key hooks: `use-tool-processor.ts` (single-file XHR + batch + SSE progress) and `use-pipeline-processor.ts`.
+
+All page components are `lazy()`-loaded. The key route is `/:toolId` rendering `ToolPage` (`apps/web/src/pages/tool-page.tsx`), which looks up metadata from shared constants and the frontend tool registry.
+
+## Database
+
+SQLite via Drizzle ORM. Schema: `apps/api/src/db/schema.ts`. Migrations in `apps/api/drizzle/`.
+
+Tables: users, teams, sessions, settings (key-value), jobs, apiKeys, pipelines, auditLog, roles, userFiles.
+
+## Testing
+
+- `tests/unit/` -- Vitest unit tests
+- `tests/integration/` -- Vitest integration tests (one per tool/feature, full API)
+- `tests/e2e/` -- Playwright specs (Chromium primary, Firefox/WebKit for cross-browser)
+- `tests/fixtures/` -- Small test images in various formats
+
+Vitest uses single-fork pool (shared SQLite connection), 30s timeouts, and injects test env vars. Playwright auth setup project logs in and saves storage state; spins up both dev servers with a fresh test DB.
+
+## Pre-commit Hooks
+
+Husky + lint-staged runs `biome check --write` on staged `*.{ts,tsx,js,jsx,json}` files before every commit. If a commit fails, fix the lint issues rather than bypassing the hook.
+
+## Do Not Modify Config Files
+
+Biome, TypeScript, and editor config files are protected by hooks. Fix the code to satisfy the linter/compiler, not the other way around. This prevents a common AI failure mode where rules get weakened instead of code getting fixed.
+
+## Model Routing for Subagents
+
+Always use **Opus 4.7, Max Effort, 1M context** for every agent and subagent. No exceptions. No model downgrading.
+
+## Strategic Compaction
+
+When context gets large, compact at logical phase boundaries:
+
+- **Good times to compact**: After research and before planning. After debugging and before implementing the fix. After completing a major feature.
+- **Bad times to compact**: Mid-implementation. While actively debugging. During a multi-step refactor.
+- **Survives compaction**: This CLAUDE.md, active tasks, git state, memory files
+- **Lost on compaction**: Intermediate reasoning, file contents previously read, conversation flow

apps/api/src/index.ts

@@ -23,6 +23,7 @@ import { analyticsRoutes } from "./routes/analytics.js";
 import { apiKeyRoutes } from "./routes/api-keys.js";
 import { auditLogRoutes } from "./routes/audit-log.js";
 import { registerBatchRoutes } from "./routes/batch.js";
+import { configRoutes } from "./routes/config.js";
 import { docsRoutes } from "./routes/docs.js";
 import { registerFeatureRoutes } from "./routes/features.js";
 import { registerFetchUrlsRoute } from "./routes/fetch-urls.js";
@@ -172,6 +173,9 @@ await app.register(cookie, {
   hook: "onRequest",
 });
 
+// Public config routes (no auth required)
+await configRoutes(app);
+
 // Auth middleware (must be registered before routes it protects)
 await authMiddleware(app);
 

apps/api/src/routes/config.ts

@@ -0,0 +1,14 @@
+import { eq } from "drizzle-orm";
+import type { FastifyInstance } from "fastify";
+import { db, schema } from "../db/index.js";
+
+export async function configRoutes(app: FastifyInstance): Promise<void> {
+  app.get("/api/v1/config/locale", async (_request, reply) => {
+    const row = db
+      .select()
+      .from(schema.settings)
+      .where(eq(schema.settings.key, "defaultLocale"))
+      .get();
+    return reply.send({ defaultLocale: row?.value ?? "en" });
+  });
+}

apps/docs/guide/translations.md

@@ -1,78 +1,129 @@
 # Translation guide
 
-SnapOtter ships with English by default. The i18n system is designed so adding a new language is straightforward.
+SnapOtter ships with 21 languages out of the box. The i18n system uses a lightweight custom runtime with TypeScript-enforced locale completeness and dynamic code-splitting.
+
+## Supported languages
+
+| Code | Language | Native Name | Direction |
+|------|----------|-------------|-----------|
+| `en` | English | English | LTR |
+| `zh-CN` | Chinese (Simplified) | 简体中文 | LTR |
+| `zh-TW` | Chinese (Traditional) | 繁體中文 | LTR |
+| `ja` | Japanese | 日本語 | LTR |
+| `ko` | Korean | 한국어 | LTR |
+| `es` | Spanish | Español | LTR |
+| `fr` | French | Français | LTR |
+| `it` | Italian | Italiano | LTR |
+| `pt-BR` | Portuguese (Brazil) | Português (Brasil) | LTR |
+| `de` | German | Deutsch | LTR |
+| `nl` | Dutch | Nederlands | LTR |
+| `sv` | Swedish | Svenska | LTR |
+| `ru` | Russian | Русский | LTR |
+| `pl` | Polish | Polski | LTR |
+| `uk` | Ukrainian | Українська | LTR |
+| `ar` | Arabic | العربية | RTL |
+| `tr` | Turkish | Türkçe | LTR |
+| `hi` | Hindi | हिन्दी | LTR |
+| `vi` | Vietnamese | Tiếng Việt | LTR |
+| `id` | Indonesian | Bahasa Indonesia | LTR |
+| `th` | Thai | ไทย | LTR |
+
+## How language detection works
+
+SnapOtter uses a three-tier resolution order:
+
+1. **User preference** -- stored in `localStorage("snapotter-locale")` and synced to user settings when authenticated
+2. **Browser auto-detect** -- walks the `navigator.languages` array with BCP 47 prefix matching
+3. **Instance default** -- the admin's `DEFAULT_LOCALE` env var (fetched from `GET /api/v1/config/locale`)
+4. **English fallback** -- always available
+
+Users can change language from:
+- The **footer Globe selector** (desktop, always visible)
+- The **login page** language selector (pre-auth)
+- The **Settings > General** section (per-user preference)
+- The **mobile sidebar** language dropdown
+- The **Settings > System** section sets the instance-wide default (admin only)
 
 ## How translations work
 
-All UI strings live in `packages/shared/src/i18n/`. The reference file is `en.ts`, which exports a typed object with every string the app uses. Other languages are separate files (e.g., `de.ts`, `fr.ts`) that export the same shape.
+All UI strings live in `packages/shared/src/i18n/`. The reference file is `en.ts`, which exports a typed object with every string the app uses (~1500 keys). Other languages are separate files (e.g., `de.ts`, `fr.ts`) that export the same shape.
 
-The `TranslationKeys` type is derived from the English file, so TypeScript will catch any missing keys in any translation file.
+The `TranslationKeys` type uses `DeepStringRecord` to accept any string value while enforcing the key structure. TypeScript catches missing keys in any translation file at compile time.
+
+Only the active locale is loaded at runtime via dynamic `import()`, keeping the main bundle small.
+
+## Using translations in components
+
+```tsx
+import { useTranslation } from "@/contexts/i18n-context";
+import { format, plural } from "@/lib/format";
+
+function MyComponent() {
+  const { t, locale, setLocale } = useTranslation();
+  
+  return (
+    <div>
+      <h1>{t.common.settings}</h1>
+      <p>{format(t.settings.people.deleteConfirm, { username: "admin" })}</p>
+      <p>{plural(count, t.automate.fileCount, t.automate.fileCountPlural)}</p>
+    </div>
+  );
+}
+```
 
 ## Requesting a translation
 
-To request a new language or report a mistranslation, open a [GitHub Issue](https://github.com/snapotter-hq/snapotter/issues) with:
+To request a new language or report a mistranslation, open a [GitHub Issue](https://github.com/snapotter-hq/SnapOtter/issues) with:
 
 - The language name and locale code (e.g., German / `de`)
 - Any specific strings or sections you want translated
 - If you have a translation ready, paste the translated strings directly in the issue
 
-We do not accept pull requests. Submitting translations via issues is the right path.
-
 ## How to create a translation (for your own fork)
 
-If you are running a fork and want to add a language yourself:
-
 ### 1. Copy the reference file
 
 ```bash
-cp packages/shared/src/i18n/en.ts packages/shared/src/i18n/de.ts
+cp packages/shared/src/i18n/en.ts packages/shared/src/i18n/XX.ts
 ```
 
 ### 2. Translate the strings
 
-Open your new file and translate every string value. Keep the object structure and keys exactly the same - only change the values.
+Open your new file and translate every string value. Keep the object structure and keys exactly the same.
 
 ```ts
-// packages/shared/src/i18n/de.ts
-export const de = {
+import type { TranslationKeys } from "./en.js";
+
+export const xx: TranslationKeys = {
   common: {
-    upload: "Vom Computer hochladen",
-    process: "Verarbeiten",
-    download: "Herunterladen",
-    cancel: "Abbrechen",
+    upload: "Your translation here",
     // ... translate all entries
   },
-  tools: {
-    resize: {
-      name: "Grosse andern",
-      description: "Grosse nach Pixeln, Prozent oder Social-Media-Vorgaben andern",
-    },
-    // ... translate all tool entries
-  },
-  // ... translate all sections: settings, auth, pipeline, nav
+  // ... translate all sections
 } as const;
 ```
 
-Things to keep in mind:
+Rules:
+- Do not translate object keys, only string values
+- Keep `as const` at the end
+- Import `TranslationKeys` from `./en.js` and type your export
+- Keep `{variable}` placeholders exactly as-is
+- Arrays (`rotatingPhrases`, `progressMessages`) must have the same number of entries
+- Do not translate: SnapOtter, JPEG, PNG, WebP, EXIF, API, and other technical terms
 
-- Do not translate object keys, only values.
-- Keep the `as const` assertion at the end.
-- If a string is the same in your language (technical terms, proper nouns), leave the English value.
+### 3. Register the locale
 
-### 3. Export the new language
-
-Edit `packages/shared/src/i18n/index.ts` to include your language:
+Add your locale to `SUPPORTED_LOCALES` in `packages/shared/src/i18n/index.ts`:
 
 ```ts
-export type { TranslationKeys } from "./en.js";
-export { en } from "./en.js";
-export { de } from "./de.js";
+{ code: "xx", name: "Language Name", nativeName: "Native Name", dir: "ltr" },
 ```
 
 ### 4. Verify
 
 ```bash
 pnpm typecheck    # catches missing or mistyped keys
+pnpm lint         # formatting check
 pnpm dev          # manually verify strings appear correctly
 ```
 
@@ -80,13 +131,25 @@ pnpm dev          # manually verify strings appear correctly
 
 When adding a new feature that needs new UI strings:
 
-1. Add the new keys to `packages/shared/src/i18n/en.ts` first. This is the reference file.
-2. Run `pnpm typecheck` to make sure all language files still satisfy the `TranslationKeys` type.
+1. Add the new keys to `en.ts` first (the reference file)
+2. Run `pnpm typecheck` -- every locale file will fail if missing the new key
+3. Add the new key to all locale files (use English as a temporary fallback)
+
+## Configuration
+
+Set the instance default language via environment variable:
+
+```yaml
+DEFAULT_LOCALE: "de"  # German as the default for all new users
+```
 
 ## File reference
 
 | File | Purpose |
 |------|---------|
-| `packages/shared/src/i18n/en.ts` | English strings (reference locale) |
-| `packages/shared/src/i18n/index.ts` | Exports all locales and the `TranslationKeys` type |
-| `packages/shared/src/constants.ts` | Tool registry (names/descriptions also live here) |
+| `packages/shared/src/i18n/en.ts` | English strings (reference locale, ~1500 keys) |
+| `packages/shared/src/i18n/index.ts` | `SUPPORTED_LOCALES`, `loadTranslations()`, type exports |
+| `packages/shared/src/i18n/<locale>.ts` | Per-language translation files |
+| `apps/web/src/contexts/i18n-context.tsx` | `I18nProvider`, `useTranslation()` hook |
+| `apps/web/src/lib/format.ts` | `format()`, `plural()`, `formatFileSize()` helpers |
+| `apps/api/src/routes/config.ts` | `GET /api/v1/config/locale` public endpoint |

apps/web/src/App.tsx

@@ -1,9 +1,10 @@
-import { APP_VERSION, shouldShowConsent } from "@snapotter/shared";
+import { APP_VERSION, en, shouldShowConsent } from "@snapotter/shared";
 import { Component, type ErrorInfo, lazy, type ReactNode, Suspense, useEffect } from "react";
 import { BrowserRouter, Navigate, Route, Routes, useLocation } from "react-router-dom";
 import { Toaster } from "sonner";
 import { ConnectionMonitor } from "./components/common/connection-monitor";
 import { KeyboardShortcutProvider } from "./components/common/keyboard-shortcut-provider";
+import { I18nProvider } from "./contexts/i18n-context";
 import { useAuth } from "./hooks/use-auth";
 import { identify, initAnalytics, setAnalyticsConsent } from "./lib/analytics";
 import { useAnalyticsStore } from "./stores/analytics-store";
@@ -55,9 +56,9 @@ class ErrorBoundary extends Component<
       return (
         <div className="flex h-screen items-center justify-center bg-background text-foreground">
           <div className="text-center space-y-4 max-w-md px-6">
-            <h1 className="text-xl font-semibold">Something went wrong</h1>
+            <h1 className="text-xl font-semibold">{en.common.somethingWentWrong}</h1>
             <p className="text-sm text-muted-foreground">
-              {this.state.error?.message || "An unexpected error occurred."}
+              {this.state.error?.message || en.common.unexpectedError}
             </p>
             <button
               type="button"
@@ -67,7 +68,7 @@ class ErrorBoundary extends Component<
               }}
               className="px-4 py-2 rounded-lg bg-primary text-primary-foreground text-sm font-medium"
             >
-              Go Home
+              {en.common.goHome}
             </button>
           </div>
         </div>
@@ -132,7 +133,7 @@ function AuthGuard({ children }: { children: React.ReactNode }) {
       <div className="flex h-screen items-center justify-center bg-background text-foreground">
         <div className="text-center space-y-3">
           <div className="h-8 w-8 border-2 border-primary border-t-transparent rounded-full animate-spin mx-auto" />
-          <p className="text-sm text-muted-foreground">Loading...</p>
+          <p className="text-sm text-muted-foreground">{en.common.loading}</p>
         </div>
       </div>
     );
@@ -205,36 +206,41 @@ export function App() {
 
   return (
     <ErrorBoundary>
-      <ConnectionMonitor />
-      <Toaster position="bottom-right" />
-      <BrowserRouter>
-        <KeyboardShortcutProvider>
-          <AuthGuard>
-            <Suspense fallback={<PageLoader />}>
-              <Routes>
-                <Route path="/login" element={<LoginPage />} />
-                <Route path="/change-password" element={<ChangePasswordPage />} />
-                <Route path="/automate" element={<AutomatePage />} />
-                <Route path="/files" element={<FilesPage />} />
-                <Route path="/fullscreen" element={<FullscreenGridPage />} />
-                <Route path="/privacy" element={<PrivacyPolicyPage />} />
-                {/* Redirects: old color tools consolidated into adjust-colors */}
-                <Route
-                  path="/brightness-contrast"
-                  element={<Navigate to="/adjust-colors" replace />}
-                />
-                <Route path="/saturation" element={<Navigate to="/adjust-colors" replace />} />
-                <Route path="/color-channels" element={<Navigate to="/adjust-colors" replace />} />
-                <Route path="/color-effects" element={<Navigate to="/adjust-colors" replace />} />
-                <Route path="/analytics-consent" element={<AnalyticsConsentPage />} />
-                <Route path="/editor" element={<EditorPage />} />
-                <Route path="/:toolId" element={<ToolPage />} />
-                <Route path="/" element={<HomePage />} />
-              </Routes>
-            </Suspense>
-          </AuthGuard>
-        </KeyboardShortcutProvider>
-      </BrowserRouter>
+      <I18nProvider>
+        <ConnectionMonitor />
+        <Toaster position="bottom-right" />
+        <BrowserRouter>
+          <KeyboardShortcutProvider>
+            <AuthGuard>
+              <Suspense fallback={<PageLoader />}>
+                <Routes>
+                  <Route path="/login" element={<LoginPage />} />
+                  <Route path="/change-password" element={<ChangePasswordPage />} />
+                  <Route path="/automate" element={<AutomatePage />} />
+                  <Route path="/files" element={<FilesPage />} />
+                  <Route path="/fullscreen" element={<FullscreenGridPage />} />
+                  <Route path="/privacy" element={<PrivacyPolicyPage />} />
+                  {/* Redirects: old color tools consolidated into adjust-colors */}
+                  <Route
+                    path="/brightness-contrast"
+                    element={<Navigate to="/adjust-colors" replace />}
+                  />
+                  <Route path="/saturation" element={<Navigate to="/adjust-colors" replace />} />
+                  <Route
+                    path="/color-channels"
+                    element={<Navigate to="/adjust-colors" replace />}
+                  />
+                  <Route path="/color-effects" element={<Navigate to="/adjust-colors" replace />} />
+                  <Route path="/analytics-consent" element={<AnalyticsConsentPage />} />
+                  <Route path="/editor" element={<EditorPage />} />
+                  <Route path="/:toolId" element={<ToolPage />} />
+                  <Route path="/" element={<HomePage />} />
+                </Routes>
+              </Suspense>
+            </AuthGuard>
+          </KeyboardShortcutProvider>
+        </BrowserRouter>
+      </I18nProvider>
     </ErrorBoundary>
   );
 }

apps/web/src/components/common/before-after-slider.tsx

@@ -1,4 +1,6 @@
 import { type PointerEvent, useCallback, useEffect, useRef, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
+import { format } from "@/lib/format";
 
 interface BeforeAfterSliderProps {
   /** URL or data URL of original image. */
@@ -33,6 +35,7 @@ export function BeforeAfterSlider({
   afterSize,
   initialPosition = 50,
 }: BeforeAfterSliderProps) {
+  const { t } = useTranslation();
   const containerRef = useRef<HTMLDivElement>(null);
   const [position, setPosition] = useState(initialPosition); // percentage 0-100
   const [isDragging, setIsDragging] = useState(false);
@@ -160,10 +163,10 @@ export function BeforeAfterSlider({
 
         {/* Labels */}
         <div className="absolute top-2 left-2 px-2 py-0.5 rounded bg-black/50 text-white text-xs font-medium pointer-events-none">
-          Original
+          {t.comparison.original}
         </div>
         <div className="absolute top-2 right-2 px-2 py-0.5 rounded bg-black/50 text-white text-xs font-medium pointer-events-none">
-          Processed
+          {t.comparison.processed}
         </div>
       </div>
 
@@ -176,10 +179,10 @@ export function BeforeAfterSlider({
           <span className="px-2 py-1 rounded bg-primary/10 text-primary font-medium">
             Processed: {formatSize(afterSize)}
             {savingsPercent !== null && Number(savingsPercent) > 0 && (
-              <span className="ml-1">({savingsPercent}% smaller)</span>
+              <span className="ms-1">({savingsPercent}% smaller)</span>
             )}
             {savingsPercent !== null && Number(savingsPercent) < 0 && (
-              <span className="ml-1">({Math.abs(Number(savingsPercent))}% larger)</span>
+              <span className="ms-1">({Math.abs(Number(savingsPercent))}% larger)</span>
             )}
           </span>
         </div>

apps/web/src/components/common/collapsible-section.tsx

@@ -28,7 +28,7 @@ export function CollapsibleSection({
         ) : (
           <ChevronRight className="h-3 w-3 shrink-0" />
         )}
-        <span className="flex-1 text-left">{title}</span>
+        <span className="flex-1 text-start">{title}</span>
         {warning && <AlertTriangle className="h-3 w-3 text-amber-500 shrink-0" />}
         {badge && (
           <span className="px-1.5 py-0.5 rounded bg-muted text-muted-foreground text-[10px]">

apps/web/src/components/common/connection-banner.tsx

@@ -1,7 +1,9 @@
 import { CheckCircle2, Loader2, WifiOff } from "lucide-react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useConnectionStore } from "@/stores/connection-store";
 
 export function ConnectionBanner() {
+  const { t } = useTranslation();
   const status = useConnectionStore((s) => s.status);
 
   if (status === "connected") return null;
@@ -11,19 +13,19 @@ export function ConnectionBanner() {
       bg: "bg-amber-500 dark:bg-amber-600",
       text: "text-amber-950 dark:text-amber-50",
       icon: <Loader2 className="h-4 w-4 animate-spin" />,
-      message: "Reconnecting to server\u2026",
+      message: t.errors.reconnecting,
     },
     offline: {
       bg: "bg-amber-500 dark:bg-amber-600",
       text: "text-amber-950 dark:text-amber-50",
       icon: <WifiOff className="h-4 w-4" />,
-      message: "You\u2019re offline",
+      message: t.errors.offline,
     },
     reconnected: {
       bg: "bg-emerald-500 dark:bg-emerald-600",
       text: "text-emerald-950 dark:text-emerald-50",
       icon: <CheckCircle2 className="h-4 w-4" />,
-      message: "Connected",
+      message: t.errors.connected,
     },
   }[status];
 

apps/web/src/components/common/dropzone.tsx

@@ -1,5 +1,6 @@
 import { FileImage, ImageUp, Upload } from "lucide-react";
 import { type DragEvent, useCallback, useEffect, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useUrlImport } from "@/hooks/use-url-import";
 import { cn } from "@/lib/utils";
 import { UrlImportModal } from "./url-import-modal";
@@ -111,6 +112,7 @@ export function Dropzone({
   fileFilter,
   acceptDescription,
 }: DropzoneProps) {
+  const { t } = useTranslation();
   const checkFile = fileFilter ?? isImageFile;
   const resolvedAccept = expandAccept(accept);
   const [isDragging, setIsDragging] = useState(false);
@@ -129,13 +131,13 @@ export function Dropzone({
     const file = await importSingleUrl(url);
     if (file) {
       if (!checkFile(file)) {
-        setUrlError(acceptDescription ?? "This file type is not supported by this tool");
+        setUrlError(acceptDescription ?? t.dropzone.unsupportedFileType);
       } else {
         setUrlInput("");
         onUrlImport?.(file);
       }
     } else {
-      setUrlError("Could not fetch image from URL");
+      setUrlError(t.dropzone.urlFetchFailed);
     }
     setUrlLoading(false);
   }, [urlInput, importSingleUrl, onUrlImport, checkFile, acceptDescription]);
@@ -235,11 +237,9 @@ export function Dropzone({
         </div>
         <div className="flex flex-col items-center gap-1.5">
           <p className={cn("font-medium", compact ? "text-sm" : "text-base", "text-foreground/80")}>
-            Drop your images here
-          </p>
-          <p className="text-sm text-muted-foreground/70">
-            click anywhere to browse, or paste from clipboard
+            {t.dropzone.dropPrompt}
           </p>
+          <p className="text-sm text-muted-foreground/70">{t.dropzone.browseOrPaste}</p>
         </div>
         <button
           type="button"
@@ -254,10 +254,10 @@ export function Dropzone({
           )}
         >
           <Upload className="h-4 w-4" />
-          Upload
+          {t.common.upload}
         </button>
         <p className="text-xs text-muted-foreground/50">
-          {acceptDescription ?? "PNG, JPG, WebP, HEIC, RAW, PSD, and 65+ formats"}
+          {acceptDescription ?? t.dropzone.defaultFormats}
         </p>
 
         {!compact && onUrlImport && (
@@ -282,7 +282,7 @@ export function Dropzone({
                   }
                 }}
                 onClick={(e) => e.stopPropagation()}
-                placeholder="Paste image URL..."
+                placeholder={t.dropzone.urlPlaceholder}
                 className="flex-1 rounded-md border border-border bg-background px-3 py-1.5 text-sm text-foreground placeholder:text-muted-foreground focus:border-primary focus:outline-none"
                 disabled={urlLoading}
               />
@@ -307,7 +307,7 @@ export function Dropzone({
               }}
               className="text-xs text-primary hover:text-primary/80"
             >
-              Import multiple URLs...
+              {t.dropzone.importMultipleUrls}
             </button>
           </>
         )}
@@ -325,7 +325,7 @@ export function Dropzone({
                   className="flex items-center justify-between text-xs text-muted-foreground px-2 py-0.5"
                 >
                   <span className="truncate">{f.name}</span>
-                  <span className="shrink-0 ml-2">{(f.size / 1024).toFixed(0)} KB</span>
+                  <span className="shrink-0 ms-2">{(f.size / 1024).toFixed(0)} KB</span>
                 </div>
               ))}
             </div>

apps/web/src/components/common/file-library-modal.tsx

@@ -124,7 +124,7 @@ export function FileLibraryModal({ open, onClose, onImport }: FileLibraryModalPr
               placeholder="Search files..."
               value={searchQuery}
               onChange={handleSearchChange}
-              className="w-full pl-8 pr-3 py-1.5 text-sm bg-muted rounded-lg border border-border focus:outline-none focus:ring-2 focus:ring-primary/50 text-foreground placeholder:text-muted-foreground"
+              className="w-full ps-8 pe-3 py-1.5 text-sm bg-muted rounded-lg border border-border focus:outline-none focus:ring-2 focus:ring-primary/50 text-foreground placeholder:text-muted-foreground"
             />
           </div>
         </div>

apps/web/src/components/common/image-viewer.tsx

@@ -307,7 +307,7 @@ export function ImageViewer({
 
       {/* Info bar */}
       <div className="flex items-center justify-between px-3 py-1.5 border-t border-border text-xs text-muted-foreground shrink-0">
-        <span className="truncate mr-2">{filename}</span>
+        <span className="truncate me-2">{filename}</span>
         <div className="flex items-center gap-3 shrink-0">
           {(originalWidth || naturalWidth) != null && (originalHeight || naturalHeight) != null && (
             <span>

apps/web/src/components/common/review-panel.tsx

@@ -10,6 +10,7 @@ import {
 } from "lucide-react";
 import { useMemo, useState } from "react";
 import { Link, useNavigate } from "react-router-dom";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatFileSize, triggerDownload } from "@/lib/download";
 import { ICON_MAP } from "@/lib/icon-map";
 import { getSuggestedTools } from "@/lib/suggested-tools";
@@ -33,6 +34,7 @@ export function ReviewPanel({
   onUndo,
   currentToolId,
 }: ReviewPanelProps) {
+  const { t } = useTranslation();
   const [isExpanded, setIsExpanded] = useState(true);
   const [isSuggestionsExpanded, setIsSuggestionsExpanded] = useState(true);
   const navigate = useNavigate();
@@ -66,7 +68,7 @@ export function ReviewPanel({
         onClick={() => setIsExpanded(!isExpanded)}
         className="flex items-center justify-between w-full text-sm font-medium text-muted-foreground hover:text-foreground"
       >
-        <span>Review</span>
+        <span>{t.reviewPanel.reviewHeading}</span>
         {isExpanded ? <ChevronDown className="h-4 w-4" /> : <ChevronRight className="h-4 w-4" />}
       </button>
 
@@ -99,7 +101,7 @@ export function ReviewPanel({
               className="flex-1 py-2 rounded-lg border border-border text-muted-foreground hover:text-foreground hover:bg-muted flex items-center justify-center gap-1.5 text-xs font-medium"
             >
               <Undo2 className="h-3.5 w-3.5" />
-              Undo
+              {t.reviewPanel.undoButton}
             </button>
             <button
               type="button"
@@ -107,7 +109,7 @@ export function ReviewPanel({
               className="flex-1 py-2 rounded-lg bg-primary text-primary-foreground flex items-center justify-center gap-1.5 text-xs font-medium hover:bg-primary/90"
             >
               <Download className="h-3.5 w-3.5" />
-              Download
+              {t.common.download}
             </button>
           </div>
 
@@ -117,7 +119,7 @@ export function ReviewPanel({
             className="flex items-center justify-center gap-1.5 w-full py-2 rounded-lg border border-border text-muted-foreground hover:text-foreground hover:bg-muted text-xs font-medium"
           >
             <PenTool className="h-3.5 w-3.5" />
-            Open in Editor
+            {t.reviewPanel.openInEditor}
           </Link>
 
           {/* Suggested tools */}
@@ -129,7 +131,7 @@ export function ReviewPanel({
                 onClick={() => setIsSuggestionsExpanded(!isSuggestionsExpanded)}
                 className="flex items-center justify-between w-full text-xs font-medium text-muted-foreground hover:text-foreground"
               >
-                <span>Continue editing</span>
+                <span>{t.reviewPanel.continueEditing}</span>
                 {isSuggestionsExpanded ? (
                   <ChevronDown className="h-3.5 w-3.5" />
                 ) : (
@@ -151,7 +153,7 @@ export function ReviewPanel({
                         className="flex items-center gap-2 w-full px-2 py-1.5 rounded text-xs text-muted-foreground hover:text-foreground hover:bg-muted group"
                       >
                         <ToolIcon className="h-3.5 w-3.5 shrink-0" />
-                        <span className="flex-1 text-left">{tool.name}</span>
+                        <span className="flex-1 text-start">{tool.name}</span>
                         <ArrowRight className="h-3 w-3 opacity-0 group-hover:opacity-100 shrink-0" />
                       </button>
                     );

apps/web/src/components/common/search-bar.tsx

@@ -1,4 +1,5 @@
 import { Search } from "lucide-react";
+import { useTranslation } from "@/contexts/i18n-context";
 
 interface SearchBarProps {
   value: string;
@@ -6,7 +7,9 @@ interface SearchBarProps {
   placeholder?: string;
 }
 
-export function SearchBar({ value, onChange, placeholder = "Search tools..." }: SearchBarProps) {
+export function SearchBar({ value, onChange, placeholder }: SearchBarProps) {
+  const { t } = useTranslation();
+  const resolvedPlaceholder = placeholder ?? t.common.search;
   return (
     <div className="relative">
       <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
@@ -15,8 +18,8 @@ export function SearchBar({ value, onChange, placeholder = "Search tools..." }:
         tabIndex={0}
         value={value}
         onChange={(e) => onChange(e.target.value)}
-        placeholder={placeholder}
-        className="w-full pl-10 pr-4 py-2 rounded-lg border border-border bg-background text-sm text-foreground focus:outline-none focus:ring-2 focus:ring-primary/20"
+        placeholder={resolvedPlaceholder}
+        className="w-full ps-10 pe-4 py-2 rounded-lg border border-border bg-background text-sm text-foreground focus:outline-none focus:ring-2 focus:ring-primary/20"
       />
     </div>
   );

apps/web/src/components/common/side-by-side-comparison.tsx

@@ -1,4 +1,6 @@
 import { useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
+import { format } from "@/lib/format";
 
 interface SideBySideComparisonProps {
   beforeSrc: string;
@@ -19,6 +21,7 @@ export function SideBySideComparison({
   beforeSize,
   afterSize,
 }: SideBySideComparisonProps) {
+  const { t } = useTranslation();
   const [beforeDims, setBeforeDims] = useState<{ w: number; h: number } | null>(null);
   const [afterDims, setAfterDims] = useState<{ w: number; h: number } | null>(null);
 
@@ -34,7 +37,7 @@ export function SideBySideComparison({
         {/* Original */}
         <div className="flex-1 flex flex-col items-center gap-2">
           <span className="text-xs font-medium text-muted-foreground uppercase tracking-wide">
-            Original
+            {t.comparison.original}
           </span>
           <div className="w-full rounded-lg border border-border overflow-hidden flex items-center justify-center bg-muted/30 p-2 min-h-[200px] max-h-[60vh]">
             <img
@@ -61,7 +64,7 @@ export function SideBySideComparison({
         {/* Processed */}
         <div className="flex-1 flex flex-col items-center gap-2">
           <span className="text-xs font-medium text-muted-foreground uppercase tracking-wide">
-            Processed
+            {t.comparison.processed}
           </span>
           <div className="w-full rounded-lg border border-border overflow-hidden flex items-center justify-center bg-muted/30 p-2 min-h-[200px] max-h-[60vh]">
             <img
@@ -92,8 +95,10 @@ export function SideBySideComparison({
           className={`text-sm font-medium ${Number(savingsPercent) > 0 ? "text-green-600 dark:text-green-400" : "text-red-500"}`}
         >
           {Number(savingsPercent) > 0
-            ? `${savingsPercent}% smaller`
-            : `${Math.abs(Number(savingsPercent))}% larger`}
+            ? format(t.toolSettings["optimize-for-web"].smaller, { percent: savingsPercent })
+            : format(t.toolSettings["optimize-for-web"].larger, {
+                percent: Math.abs(Number(savingsPercent)),
+              })}
         </p>
       )}
     </div>

apps/web/src/components/common/tool-card.tsx

@@ -3,7 +3,9 @@ import { PYTHON_SIDECAR_TOOLS, TOOL_BUNDLE_MAP } from "@snapotter/shared";
 import { Clock, Download, FileImage, Loader2, Star } from "lucide-react";
 import { useMemo } from "react";
 import { Link } from "react-router-dom";
+import { useTranslation } from "@/contexts/i18n-context";
 import { ICON_MAP } from "@/lib/icon-map";
+import { getToolName } from "@/lib/tool-i18n";
 import { cn } from "@/lib/utils";
 import { useFeaturesStore } from "@/stores/features-store";
 
@@ -12,6 +14,7 @@ interface ToolCardProps {
 }
 
 export function ToolCard({ tool }: ToolCardProps) {
+  const { t } = useTranslation();
   const IconComponent =
     (ICON_MAP[tool.icon] as React.ComponentType<{ className?: string }>) ?? FileImage;
 
@@ -34,7 +37,7 @@ export function ToolCard({ tool }: ToolCardProps) {
       <button
         type="button"
         className="opacity-0 group-hover:opacity-100 transition-opacity absolute -left-5"
-        title="Add to favourites"
+        title={t.toolCard.addToFavourites}
       >
         <Star className="h-3 w-3 text-muted-foreground hover:text-yellow-500" />
       </button>
@@ -47,10 +50,12 @@ export function ToolCard({ tool }: ToolCardProps) {
         )}
       >
         <IconComponent className="h-5 w-5 text-muted-foreground" />
-        <span className="text-sm font-medium text-foreground">{tool.name}</span>
+        <span className="text-sm font-medium text-foreground">
+          {getToolName(t, tool.id, tool.name)}
+        </span>
         {tool.experimental && (
           <span className="text-[10px] px-1.5 py-0.5 rounded bg-orange-100 text-orange-600 font-medium">
-            Experimental
+            {t.common.experimental}
           </span>
         )}
         {aiStatus === "not_installed" && <Download className="h-3.5 w-3.5 text-muted-foreground" />}

apps/web/src/components/common/url-import-modal.tsx

@@ -1,6 +1,8 @@
 import { AlertCircle, Check, Clock, Link, Loader2, RotateCw, X } from "lucide-react";
 import { useCallback, useEffect, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { type UrlImportEntry, useUrlImport } from "@/hooks/use-url-import";
+import { format } from "@/lib/format";
 import { extractUrls } from "@/lib/url-parser";
 
 // ── Types ──────────────────────────────────────────────────────
@@ -42,6 +44,7 @@ function filenameFromUrl(url: string): string {
 // ── Component ──────────────────────────────────────────────────
 
 export function UrlImportModal({ onClose, onImport }: UrlImportModalProps) {
+  const { t } = useTranslation();
   const [text, setText] = useState("");
   const [adding, setAdding] = useState(false);
 
@@ -108,7 +111,7 @@ export function UrlImportModal({ onClose, onImport }: UrlImportModalProps) {
         {/* Header */}
         <div className="flex items-center gap-3 px-4 py-3 border-b border-border shrink-0">
           <Link className="h-5 w-5 text-primary" />
-          <h2 className="text-sm font-semibold text-foreground flex-1">Import from URLs</h2>
+          <h2 className="text-sm font-semibold text-foreground flex-1">{t.urlImport.title}</h2>
           <button
             type="button"
             onClick={handleClose}
@@ -130,9 +133,7 @@ export function UrlImportModal({ onClose, onImport }: UrlImportModalProps) {
             }
             className="w-full min-h-[120px] max-h-[240px] resize-y rounded-lg border border-border bg-muted px-3 py-2 text-sm font-mono text-foreground placeholder:text-muted-foreground focus:outline-none focus:ring-2 focus:ring-primary/50"
           />
-          <p className="text-xs text-muted-foreground">
-            Supports plain URLs, bulleted lists, numbered lists, and markdown links
-          </p>
+          <p className="text-xs text-muted-foreground">{t.urlImport.placeholder}</p>
 
           {/* Progress list */}
           {hasResults && (
@@ -167,7 +168,9 @@ export function UrlImportModal({ onClose, onImport }: UrlImportModalProps) {
         {/* Footer */}
         <div className="flex items-center justify-between px-4 py-3 border-t border-border shrink-0">
           <span className="text-xs text-muted-foreground">
-            {hasResults && !importing ? `${readyCount} of ${entries.length} ready` : ""}
+            {hasResults && !importing
+              ? format(t.urlImport.readyCount, { ready: readyCount, total: entries.length })
+              : ""}
           </span>
           <div className="flex items-center gap-2">
             {hasResults && !importing ? (
@@ -188,12 +191,10 @@ export function UrlImportModal({ onClose, onImport }: UrlImportModalProps) {
                   {adding ? (
                     <>
                       <Loader2 className="h-4 w-4 animate-spin" />
-                      Adding...
+                      {t.urlImport.adding}
                     </>
                   ) : (
-                    <>
-                      Add {readyCount} Image{readyCount !== 1 ? "s" : ""}
-                    </>
+                    format(t.urlImport.addButton, { count: readyCount })
                   )}
                 </button>
               </>
@@ -204,7 +205,7 @@ export function UrlImportModal({ onClose, onImport }: UrlImportModalProps) {
                   onClick={handleClose}
                   className="px-4 py-2 text-sm rounded-lg border border-border text-foreground hover:bg-muted"
                 >
-                  Cancel
+                  {t.common.cancel}
                 </button>
                 <button
                   type="button"
@@ -215,10 +216,10 @@ export function UrlImportModal({ onClose, onImport }: UrlImportModalProps) {
                   {importing ? (
                     <>
                       <Loader2 className="h-4 w-4 animate-spin" />
-                      Importing...
+                      {t.urlImport.adding}
                     </>
                   ) : (
-                    "Import"
+                    t.urlImport.importButton
                   )}
                 </button>
               </>

apps/web/src/components/editor/common/context-menu.tsx

@@ -259,7 +259,7 @@ export function ContextMenu({
             onClick={item.action}
             disabled={item.disabled}
             className={cn(
-              "flex w-full items-center gap-2.5 px-3 py-1.5 text-left text-sm",
+              "flex w-full items-center gap-2.5 px-3 py-1.5 text-start text-sm",
               "text-foreground hover:bg-muted transition-colors",
               "disabled:cursor-not-allowed disabled:opacity-40",
             )}

apps/web/src/components/editor/common/export-dialog.tsx

@@ -820,7 +820,7 @@ export function AutosaveRecoveryBanner({
     <div className="flex items-center gap-3 px-4 py-2 bg-yellow-500/10 border-b border-yellow-500/30 text-xs">
       <Save size={14} className="text-yellow-600 shrink-0" />
       <span className="text-foreground">Recovered unsaved work from {timeStr}.</span>
-      <div className="flex items-center gap-2 ml-auto">
+      <div className="flex items-center gap-2 ms-auto">
         <button
           type="button"
           onClick={onRestore}

apps/web/src/components/editor/common/slider-row.tsx

@@ -45,7 +45,7 @@ export function SliderRow({
             onChange(Math.max(min, Math.min(max, v)));
           }
         }}
-        className="w-14 px-1 py-0.5 text-xs text-right bg-muted border border-border rounded text-foreground"
+        className="w-14 px-1 py-0.5 text-xs text-end bg-muted border border-border rounded text-foreground"
       />
     </div>
   );

apps/web/src/components/editor/common/welcome-screen.tsx

@@ -2,12 +2,14 @@
 
 import { FilePlus, ImagePlus } from "lucide-react";
 import { useCallback, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useEditorStore } from "@/stores/editor-store";
 import { NewDocumentDialog } from "./new-document-dialog";
 
 const ACCEPTED_TYPES = ".png,.jpg,.jpeg,.webp,.gif,.bmp,.tiff,.svg,.avif,.svgz";
 
 export function WelcomeScreen() {
+  const { t } = useTranslation();
   const [showNewDoc, setShowNewDoc] = useState(false);
   const [isDragOver, setIsDragOver] = useState(false);
   const loadImage = useEditorStore((s) => s.loadImage);
@@ -70,8 +72,10 @@ export function WelcomeScreen() {
           }`}
         >
           <div className="text-center">
-            <h2 className="text-xl font-semibold text-foreground mb-1">Image Editor</h2>
-            <p className="text-sm text-muted-foreground">Drop an image here to get started</p>
+            <h2 className="text-xl font-semibold text-foreground mb-1">
+              {t.editor.welcome.heading}
+            </h2>
+            <p className="text-sm text-muted-foreground">{t.editor.welcome.dropDescription}</p>
           </div>
 
           <div className="flex flex-col gap-2 w-full">
@@ -81,7 +85,7 @@ export function WelcomeScreen() {
               className="flex items-center gap-3 w-full px-4 py-3 bg-primary text-primary-foreground rounded-lg hover:bg-primary/90 transition-colors"
             >
               <ImagePlus size={20} />
-              <span className="text-sm font-medium">Open Image</span>
+              <span className="text-sm font-medium">{t.editor.welcome.openImageButton}</span>
             </button>
 
             <button
@@ -90,11 +94,11 @@ export function WelcomeScreen() {
               className="flex items-center gap-3 w-full px-4 py-3 bg-muted text-foreground rounded-lg hover:bg-muted/80 transition-colors"
             >
               <FilePlus size={20} />
-              <span className="text-sm font-medium">New Document</span>
+              <span className="text-sm font-medium">{t.editor.welcome.newDocumentButton}</span>
             </button>
           </div>
 
-          <p className="text-xs text-muted-foreground">Or paste from clipboard (Ctrl+V)</p>
+          <p className="text-xs text-muted-foreground">{t.editor.welcome.pasteHint}</p>
         </div>
       </section>
 

apps/web/src/components/editor/editor-menu-bar.tsx

@@ -386,11 +386,11 @@ function MenuItemRow({ item, onClose }: { item: MenuItem; onClose: () => void })
           data-testid={`menu-item-${toTestId(item.label)}`}
         >
           <span>{item.label}</span>
-          <ChevronRight size={12} className="ml-4 text-muted-foreground" />
+          <ChevronRight size={12} className="ms-4 text-muted-foreground" />
         </div>
         {submenuOpen && (
           <div
-            className="absolute left-full top-0 ml-0.5 min-w-[180px] bg-card border border-border rounded-md shadow-lg py-1 z-[60]"
+            className="absolute left-full top-0 ms-0.5 min-w-[180px] bg-card border border-border rounded-md shadow-lg py-1 z-[60]"
             role="menu"
             onMouseEnter={handleEnter}
             onMouseLeave={handleLeave}
@@ -410,7 +410,7 @@ function MenuItemRow({ item, onClose }: { item: MenuItem; onClose: () => void })
       <button
         type="button"
         className={cn(
-          "flex items-center justify-between w-full px-3 py-1 text-xs cursor-default select-none rounded-sm text-left",
+          "flex items-center justify-between w-full px-3 py-1 text-xs cursor-default select-none rounded-sm text-start",
           item.disabled
             ? "text-muted-foreground/50 pointer-events-none"
             : "text-foreground hover:bg-accent hover:text-accent-foreground",
@@ -429,7 +429,7 @@ function MenuItemRow({ item, onClose }: { item: MenuItem; onClose: () => void })
           {item.label}
         </span>
         {item.shortcut && (
-          <span className="ml-6 text-[10px] text-muted-foreground">{item.shortcut}</span>
+          <span className="ms-6 text-[10px] text-muted-foreground">{item.shortcut}</span>
         )}
       </button>
       {item.dividerAfter && <div className="my-1 border-t border-border" />}

apps/web/src/components/editor/editor-status-bar.tsx

@@ -31,7 +31,7 @@ export function EditorStatusBar() {
             const val = Number.parseFloat(e.target.value);
             if (!Number.isNaN(val) && val > 0) setZoom(val / 100);
           }}
-          className="w-14 bg-transparent text-right text-xs border-none outline-none"
+          className="w-14 bg-transparent text-end text-xs border-none outline-none"
           min={0.01}
           max={6400}
           step={0.1}

apps/web/src/components/editor/options/eyedropper-options.tsx

@@ -33,7 +33,7 @@ export function EyedropperOptions({
     <div className="flex items-center gap-3">
       {/* Sample size dropdown */}
       <div className="relative">
-        <span className="text-xs text-muted-foreground mr-1.5">Sample:</span>
+        <span className="text-xs text-muted-foreground me-1.5">Sample:</span>
         <button
           type="button"
           onClick={() => setOpen(!open)}
@@ -84,7 +84,7 @@ export function EyedropperOptions({
                     setOpen(false);
                   }}
                   className={cn(
-                    "w-full text-left px-3 py-1.5 text-xs transition-colors",
+                    "w-full text-start px-3 py-1.5 text-xs transition-colors",
                     s.value === sampleSize
                       ? "bg-primary text-primary-foreground"
                       : "text-foreground hover:bg-muted",

apps/web/src/components/editor/options/move-options.tsx

@@ -77,7 +77,7 @@ export function MoveOptions() {
 
   return (
     <div className="flex items-center gap-1">
-      <span className="mr-2 text-xs text-muted-foreground">Align:</span>
+      <span className="me-2 text-xs text-muted-foreground">Align:</span>
 
       <OptionButton
         icon={AlignStartHorizontal}
@@ -121,7 +121,7 @@ export function MoveOptions() {
 
       <div className="mx-1 h-4 w-px bg-border" />
 
-      <span className="mr-1 text-xs text-muted-foreground">Distribute:</span>
+      <span className="me-1 text-xs text-muted-foreground">Distribute:</span>
 
       <OptionButton
         icon={ArrowLeftRight}

apps/web/src/components/editor/options/selection-options.tsx

@@ -86,13 +86,13 @@ export function SelectionOptions() {
       {/* Selection type toggle */}
       {!isMagicWand && (
         <div className="flex items-center gap-1">
-          <span className="mr-1 text-xs text-muted-foreground">Type:</span>
+          <span className="me-1 text-xs text-muted-foreground">Type:</span>
           <ToggleButton
             active={selectionType === "rect" && isMarquee}
             onClick={() => handleTypeChange("rect")}
             label="Rectangular"
           >
-            <Square className="mr-1 h-3.5 w-3.5" />
+            <Square className="me-1 h-3.5 w-3.5" />
             Rect
           </ToggleButton>
           <ToggleButton
@@ -100,11 +100,11 @@ export function SelectionOptions() {
             onClick={() => handleTypeChange("ellipse")}
             label="Elliptical"
           >
-            <Circle className="mr-1 h-3.5 w-3.5" />
+            <Circle className="me-1 h-3.5 w-3.5" />
             Ellipse
           </ToggleButton>
           <ToggleButton active={isLasso} onClick={() => handleTypeChange("lasso")} label="Lasso">
-            <PenTool className="mr-1 h-3.5 w-3.5" />
+            <PenTool className="me-1 h-3.5 w-3.5" />
             Lasso
           </ToggleButton>
         </div>
@@ -121,7 +121,7 @@ export function SelectionOptions() {
 
       {/* Selection mode buttons */}
       <div className="flex items-center gap-1">
-        <span className="mr-1 text-xs text-muted-foreground">Mode:</span>
+        <span className="me-1 text-xs text-muted-foreground">Mode:</span>
         <ToggleButton
           active={selectionMode === "new"}
           onClick={() => handleModeChange("new")}
@@ -134,7 +134,7 @@ export function SelectionOptions() {
           onClick={() => handleModeChange("add")}
           label="Add to Selection"
         >
-          <Plus className="mr-0.5 h-3 w-3" />
+          <Plus className="me-0.5 h-3 w-3" />
           Add
         </ToggleButton>
         <ToggleButton
@@ -142,7 +142,7 @@ export function SelectionOptions() {
           onClick={() => handleModeChange("subtract")}
           label="Subtract from Selection"
         >
-          <Minus className="mr-0.5 h-3 w-3" />
+          <Minus className="me-0.5 h-3 w-3" />
           Sub
         </ToggleButton>
       </div>

apps/web/src/components/editor/options/text-options.tsx

@@ -191,7 +191,7 @@ function FontDropdown({ value, onChange }: { value: string; onChange: (name: str
               key={name}
               onClick={() => handleSelect(name)}
               className={cn(
-                "w-full text-left px-3 py-1.5 text-sm hover:bg-muted transition-colors",
+                "w-full text-start px-3 py-1.5 text-sm hover:bg-muted transition-colors",
                 value === name && "bg-muted font-medium",
               )}
               style={{ fontFamily: name }}
@@ -212,7 +212,7 @@ function FontDropdown({ value, onChange }: { value: string; onChange: (name: str
               key={name}
               onClick={() => handleSelect(name)}
               className={cn(
-                "w-full text-left px-3 py-1.5 text-sm hover:bg-muted transition-colors",
+                "w-full text-start px-3 py-1.5 text-sm hover:bg-muted transition-colors",
                 value === name && "bg-muted font-medium",
               )}
               style={{ fontFamily: name }}

apps/web/src/components/editor/panels/history-panel.tsx

@@ -190,7 +190,7 @@ export function HistoryPanel() {
         >
           <Redo2 size={14} />
         </button>
-        <span className="ml-auto text-[10px] text-muted-foreground">{pastLength} / 50</span>
+        <span className="ms-auto text-[10px] text-muted-foreground">{pastLength} / 50</span>
       </div>
 
       {/* History list */}
@@ -206,7 +206,7 @@ export function HistoryPanel() {
               type="button"
               onClick={() => jumpToState(entry)}
               className={cn(
-                "flex items-center gap-2 w-full px-2 py-1.5 text-left text-xs transition-colors",
+                "flex items-center gap-2 w-full px-2 py-1.5 text-start text-xs transition-colors",
                 isCurrent && "bg-primary/10 text-foreground font-medium",
                 isFuture && "text-muted-foreground/40",
                 !isCurrent &&

apps/web/src/components/editor/panels/layers-panel.tsx

@@ -467,8 +467,8 @@ function LayerRow({
       className={cn(
         "flex items-center gap-1.5 px-1.5 py-1 rounded cursor-pointer select-none group",
         "hover:bg-muted/50 transition-colors",
-        isActive && "bg-primary/10 border-l-2 border-primary",
-        !isActive && "border-l-2 border-transparent",
+        isActive && "bg-primary/10 border-s-2 border-primary",
+        !isActive && "border-s-2 border-transparent",
       )}
       role="option"
       aria-selected={isActive}
@@ -545,7 +545,7 @@ function LayerRow({
           <button
             type="button"
             className={cn(
-              "block text-xs truncate text-left bg-transparent border-0 p-0 w-full cursor-pointer",
+              "block text-xs truncate text-start bg-transparent border-0 p-0 w-full cursor-pointer",
               isActive ? "text-foreground font-medium" : "text-muted-foreground",
             )}
             onClick={handleNameClick}
@@ -645,7 +645,7 @@ function LayerContextMenu({
             item.action();
           }}
           className={cn(
-            "flex items-center gap-2 w-full px-3 py-1.5 text-xs text-left transition-colors",
+            "flex items-center gap-2 w-full px-3 py-1.5 text-xs text-start transition-colors",
             item.disabled
               ? "text-muted-foreground/40 cursor-not-allowed"
               : "text-foreground hover:bg-muted",
@@ -1000,7 +1000,7 @@ function EffectSlider({
         onChange={(e) => onChange(Number(e.target.value))}
         className="flex-1 min-w-0"
       />
-      <span className="text-[10px] font-mono text-foreground tabular-nums w-11 text-right shrink-0">
+      <span className="text-[10px] font-mono text-foreground tabular-nums w-11 text-end shrink-0">
         {value}
         {suffix}
       </span>

apps/web/src/components/editor/panels/navigator-panel.tsx

@@ -266,7 +266,7 @@ export function NavigatorPanel() {
         >
           <Plus size={12} />
         </button>
-        <span className="text-[10px] text-muted-foreground w-9 text-right tabular-nums">
+        <span className="text-[10px] text-muted-foreground w-9 text-end tabular-nums">
           {zoomPercent}%
         </span>
       </div>

apps/web/src/components/features/feature-install-prompt.tsx

@@ -1,6 +1,8 @@
 import type { FeatureBundleState } from "@snapotter/shared";
 import { AlertCircle, Clock, Download, Loader2, RotateCcw } from "lucide-react";
 import { useEffect, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
+import { format } from "@/lib/format";
 import { useFeaturesStore } from "@/stores/features-store";
 
 const PROGRESS_MESSAGES = [
@@ -56,6 +58,7 @@ export function FeatureInstallPrompt({
   toolName,
   toolDescription,
 }: FeatureInstallPromptProps) {
+  const { t } = useTranslation();
   const { installBundle, clearError, installing, errors, startTimes, queued } = useFeaturesStore();
   const progress = installing[bundle.id] ?? null;
   const error = errors[bundle.id] ?? null;
@@ -97,10 +100,8 @@ export function FeatureInstallPrompt({
     return (
       <div className="flex flex-col items-center justify-center h-full gap-4 text-center px-4">
         <Download className="h-16 w-16 text-muted-foreground" />
-        <h2 className="text-xl font-semibold text-foreground">Feature Not Enabled</h2>
-        <p className="text-muted-foreground max-w-md">
-          This feature is not enabled. Ask your administrator to enable it in Settings.
-        </p>
+        <h2 className="text-xl font-semibold text-foreground">{t.features.notEnabledTitle}</h2>
+        <p className="text-muted-foreground max-w-md">{t.features.notEnabledDescription}</p>
       </div>
     );
   }
@@ -112,21 +113,21 @@ export function FeatureInstallPrompt({
         <h2 className="text-xl font-semibold text-foreground">{displayName}</h2>
         <p className="text-muted-foreground max-w-md">{displayDescription}</p>
         <p className="text-sm text-muted-foreground">
-          This feature requires an additional download (~{bundle.estimatedSize})
+          {format(t.features.requiresDownload, { size: bundle.estimatedSize })}
         </p>
       </div>
 
       {error && (
         <div className="flex items-center gap-2 bg-destructive/10 text-destructive rounded-lg px-4 py-3 max-w-md w-full">
           <AlertCircle className="h-4 w-4 shrink-0" />
-          <span className="text-sm flex-1 text-left">{error}</span>
+          <span className="text-sm flex-1 text-start">{error}</span>
           <button
             type="button"
             onClick={handleInstall}
             className="flex items-center gap-1 text-sm font-medium hover:opacity-80"
           >
             <RotateCcw className="h-3.5 w-3.5" />
-            Retry
+            {t.features.retryButton}
           </button>
         </div>
       )}
@@ -144,7 +145,7 @@ export function FeatureInstallPrompt({
               <Loader2 className="h-4 w-4 animate-spin shrink-0" />
               <span className="italic truncate">{PROGRESS_MESSAGES[messageIndex]}</span>
             </div>
-            {eta && <p className="text-xs text-muted-foreground shrink-0 ml-2">{eta}</p>}
+            {eta && <p className="text-xs text-muted-foreground shrink-0 ms-2">{eta}</p>}
           </div>
         </div>
       )}
@@ -152,7 +153,7 @@ export function FeatureInstallPrompt({
       {isQueued && (
         <div className="flex items-center gap-2 text-muted-foreground">
           <Clock className="h-5 w-5" />
-          <span className="text-sm font-medium">Queued for installation...</span>
+          <span className="text-sm font-medium">{t.features.queued}</span>
         </div>
       )}
 
@@ -162,7 +163,7 @@ export function FeatureInstallPrompt({
           onClick={handleInstall}
           className="px-6 py-2.5 bg-primary text-primary-foreground rounded-lg hover:bg-primary/90 font-medium"
         >
-          Enable {displayName}
+          {format(t.features.enableButton, { name: displayName })}
         </button>
       )}
     </div>

apps/web/src/components/files/file-details.tsx

@@ -195,7 +195,7 @@ function DetailRow({ label, value }: { label: string; value: string }) {
   return (
     <div className="flex justify-between items-start gap-2 px-3 py-2">
       <span className="text-xs text-muted-foreground shrink-0">{label}</span>
-      <span className="text-xs text-foreground text-right break-all">{value}</span>
+      <span className="text-xs text-foreground text-end break-all">{value}</span>
     </div>
   );
 }

apps/web/src/components/files/file-list-item.tsx

@@ -80,12 +80,12 @@ export function FileListItem({ file }: FileListItemProps) {
       </span>
 
       {/* Size */}
-      <span className="hidden sm:block text-xs text-muted-foreground shrink-0 w-16 text-right">
+      <span className="hidden sm:block text-xs text-muted-foreground shrink-0 w-16 text-end">
         {formatSize(file.size)}
       </span>
 
       {/* Date */}
-      <span className="hidden lg:block text-xs text-muted-foreground shrink-0 w-24 text-right">
+      <span className="hidden lg:block text-xs text-muted-foreground shrink-0 w-24 text-end">
         {formatDate(file.createdAt)}
       </span>
     </div>

apps/web/src/components/files/file-list.tsx

@@ -64,7 +64,7 @@ export function FileList() {
             placeholder="Search files..."
             value={inputValue}
             onChange={handleSearchChange}
-            className="w-full pl-8 pr-3 py-1.5 text-sm bg-muted rounded-lg border border-border focus:outline-none focus:ring-2 focus:ring-primary/50 text-foreground placeholder:text-muted-foreground"
+            className="w-full ps-8 pe-3 py-1.5 text-sm bg-muted rounded-lg border border-border focus:outline-none focus:ring-2 focus:ring-primary/50 text-foreground placeholder:text-muted-foreground"
           />
         </div>
       </div>

apps/web/src/components/help/help-dialog.tsx

@@ -1,6 +1,7 @@
 import { APP_VERSION } from "@snapotter/shared";
 import { BookOpen, ExternalLink, Github, Keyboard, X } from "lucide-react";
 import { useEffect } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatShortcut } from "@/hooks/use-keyboard-shortcuts";
 
 interface HelpDialogProps {
@@ -23,6 +24,7 @@ const SHORTCUTS = [
 ];
 
 export function HelpDialog({ open, onClose }: HelpDialogProps) {
+  const { t } = useTranslation();
   useEffect(() => {
     if (!open) return;
     const handler = (e: KeyboardEvent) => {
@@ -45,7 +47,7 @@ export function HelpDialog({ open, onClose }: HelpDialogProps) {
       <div className="relative bg-background border border-border rounded-xl shadow-2xl w-full max-w-lg max-h-[85vh] flex flex-col overflow-hidden">
         {/* Header */}
         <div className="flex items-center justify-between p-4 border-b border-border shrink-0">
-          <h2 className="text-lg font-semibold text-foreground">Help</h2>
+          <h2 className="text-lg font-semibold text-foreground">{t.help.heading}</h2>
           <button
             type="button"
             onClick={onClose}
@@ -61,7 +63,7 @@ export function HelpDialog({ open, onClose }: HelpDialogProps) {
           <section className="space-y-2">
             <div className="flex items-center gap-2 text-foreground">
               <BookOpen className="h-4 w-4" />
-              <h3 className="text-sm font-semibold">Getting Started</h3>
+              <h3 className="text-sm font-semibold">{t.help.gettingStarted.heading}</h3>
             </div>
             <p className="text-sm text-muted-foreground leading-relaxed">
               Select a tool from the sidebar or search for one with <Kbd keys="mod+k" />. Upload an
@@ -74,7 +76,7 @@ export function HelpDialog({ open, onClose }: HelpDialogProps) {
           <section className="space-y-3">
             <div className="flex items-center gap-2 text-foreground">
               <Keyboard className="h-4 w-4" />
-              <h3 className="text-sm font-semibold">Keyboard Shortcuts</h3>
+              <h3 className="text-sm font-semibold">{t.help.keyboardShortcuts.heading}</h3>
             </div>
             <div className="rounded-lg border border-border overflow-hidden">
               {SHORTCUTS.map((s, i) => (
@@ -95,7 +97,7 @@ export function HelpDialog({ open, onClose }: HelpDialogProps) {
           <section className="space-y-2">
             <div className="flex items-center gap-2 text-foreground">
               <Github className="h-4 w-4" />
-              <h3 className="text-sm font-semibold">Resources</h3>
+              <h3 className="text-sm font-semibold">{t.help.resources.heading}</h3>
             </div>
             <div className="flex flex-col gap-1.5">
               <a
@@ -104,7 +106,7 @@ export function HelpDialog({ open, onClose }: HelpDialogProps) {
                 rel="noopener noreferrer"
                 className="flex items-center gap-1.5 text-sm text-primary hover:underline"
               >
-                GitHub Repository
+                {t.help.resources.githubLink}
                 <ExternalLink className="h-3 w-3" />
               </a>
               <a
@@ -113,7 +115,7 @@ export function HelpDialog({ open, onClose }: HelpDialogProps) {
                 rel="noopener noreferrer"
                 className="flex items-center gap-1.5 text-sm text-primary hover:underline"
               >
-                Report an Issue
+                {t.help.resources.reportIssueLink}
                 <ExternalLink className="h-3 w-3" />
               </a>
               <a
@@ -122,7 +124,7 @@ export function HelpDialog({ open, onClose }: HelpDialogProps) {
                 rel="noopener noreferrer"
                 className="flex items-center gap-1.5 text-sm text-primary hover:underline"
               >
-                Documentation
+                {t.help.resources.docsLink}
                 <ExternalLink className="h-3 w-3" />
               </a>
               <a
@@ -131,7 +133,7 @@ export function HelpDialog({ open, onClose }: HelpDialogProps) {
                 rel="noopener noreferrer"
                 className="flex items-center gap-1.5 text-sm text-primary hover:underline"
               >
-                API Reference (Swagger)
+                {t.help.resources.apiRefLink}
                 <ExternalLink className="h-3 w-3" />
               </a>
             </div>

apps/web/src/components/layout/app-layout.tsx

@@ -1,6 +1,15 @@
-import { FolderOpen, LayoutGrid, Menu, Settings as SettingsIcon, Workflow, X } from "lucide-react";
+import {
+  FolderOpen,
+  Globe,
+  LayoutGrid,
+  Menu,
+  Settings as SettingsIcon,
+  Workflow,
+  X,
+} from "lucide-react";
 import { useState } from "react";
 import { Link } from "react-router-dom";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useMobile } from "@/hooks/use-mobile";
 import { cn } from "@/lib/utils";
 import { useConnectionStore } from "@/stores/connection-store";
@@ -30,6 +39,7 @@ export function AppLayout({
   const [settingsOpen, setSettingsOpen] = useState(false);
   const [helpOpen, setHelpOpen] = useState(false);
   const [mobileSidebarOpen, setMobileSidebarOpen] = useState(false);
+  const { t, locale, setLocale, supportedLocales } = useTranslation();
   const isMobile = useMobile();
   const connectionStatus = useConnectionStore((s) => s.status);
   const bannerVisible = connectionStatus !== "connected";
@@ -85,6 +95,22 @@ export function AppLayout({
               onNavClick={() => setMobileSidebarOpen(false)}
               expanded
             />
+            <div className="border-t border-border p-3">
+              <label className="flex items-center gap-2 text-sm text-muted-foreground">
+                <Globe className="h-4 w-4" />
+                <select
+                  value={locale}
+                  onChange={(e) => setLocale(e.target.value)}
+                  className="flex-1 bg-transparent text-sm text-foreground border-none outline-none"
+                >
+                  {supportedLocales.map((l) => (
+                    <option key={l.code} value={l.code}>
+                      {l.nativeName}
+                    </option>
+                  ))}
+                </select>
+              </label>
+            </div>
           </div>
         </>
       )}
@@ -122,7 +148,7 @@ export function AppLayout({
         {!isMobile && (
           <div className="text-center text-xs text-muted-foreground py-2 border-t border-border">
             <Link to="/privacy" className="hover:text-foreground transition-colors">
-              Privacy Policy
+              {t.common.privacyPolicy}
             </Link>
           </div>
         )}
@@ -133,17 +159,17 @@ export function AppLayout({
       {/* Mobile bottom nav */}
       {isMobile && (
         <nav className="fixed bottom-0 left-0 right-0 z-30 bg-background/95 backdrop-blur-sm border-t border-border flex items-center justify-around px-2 py-1.5">
-          <MobileNavItem icon={LayoutGrid} label="Tools" href="/" />
-          <MobileNavItem icon={Workflow} label="Automate" href="/automate" />
-          <MobileNavItem icon={ImageEditIcon} label="Editor" href="/editor" />
-          <MobileNavItem icon={FolderOpen} label="Files" href="/files" />
+          <MobileNavItem icon={LayoutGrid} label={t.appLayout.mobileNavTools} href="/" />
+          <MobileNavItem icon={Workflow} label={t.appLayout.mobileNavAutomate} href="/automate" />
+          <MobileNavItem icon={ImageEditIcon} label={t.appLayout.mobileNavEditor} href="/editor" />
+          <MobileNavItem icon={FolderOpen} label={t.appLayout.mobileNavFiles} href="/files" />
           <button
             type="button"
             onClick={() => setSettingsOpen(true)}
             className="flex flex-col items-center gap-0.5 px-3 py-1 text-muted-foreground"
           >
             <SettingsIcon className="h-5 w-5" />
-            <span className="text-[10px]">Settings</span>
+            <span className="text-[10px]">{t.appLayout.mobileNavSettings}</span>
           </button>
         </nav>
       )}

apps/web/src/components/layout/footer.tsx

@@ -1,6 +1,70 @@
 import { Globe, Moon, Sun } from "lucide-react";
+import { useEffect, useRef, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useTheme } from "@/hooks/use-theme";
 
+function LanguageSelector() {
+  const { locale, setLocale, supportedLocales } = useTranslation();
+  const [open, setOpen] = useState(false);
+  const ref = useRef<HTMLDivElement>(null);
+
+  useEffect(() => {
+    function handleClickOutside(e: MouseEvent) {
+      if (ref.current && !ref.current.contains(e.target as Node)) {
+        setOpen(false);
+      }
+    }
+    if (open) document.addEventListener("mousedown", handleClickOutside);
+    return () => document.removeEventListener("mousedown", handleClickOutside);
+  }, [open]);
+
+  const current = supportedLocales.find((l) => l.code === locale);
+
+  return (
+    <div ref={ref} className="relative">
+      <button
+        type="button"
+        onClick={() => setOpen((v) => !v)}
+        className="flex items-center gap-1.5 px-3 py-2 rounded-lg bg-card border border-border hover:bg-muted transition-colors text-sm"
+        title="Language"
+      >
+        <Globe className="h-4 w-4" />
+        {current?.nativeName ?? "English"}
+      </button>
+      {open && (
+        <div className="absolute bottom-full mb-1 right-0 w-56 max-h-72 overflow-y-auto rounded-lg border border-border bg-card shadow-lg z-50">
+          {supportedLocales.map((l) => (
+            <button
+              key={l.code}
+              type="button"
+              onClick={() => {
+                setLocale(l.code);
+                setOpen(false);
+              }}
+              className="w-full text-start px-3 py-2 text-sm hover:bg-muted flex items-center justify-between transition-colors"
+            >
+              <span className={l.code === locale ? "font-medium" : ""}>{l.nativeName}</span>
+              {l.code === locale && (
+                <svg
+                  className="h-4 w-4 text-primary"
+                  viewBox="0 0 24 24"
+                  fill="none"
+                  stroke="currentColor"
+                  strokeWidth="2"
+                  role="img"
+                  aria-label="Selected"
+                >
+                  <polyline points="20 6 9 17 4 12" />
+                </svg>
+              )}
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}
+
 export function Footer() {
   const { resolvedTheme, toggleTheme } = useTheme();
 
@@ -14,14 +78,7 @@ export function Footer() {
       >
         {resolvedTheme === "dark" ? <Sun className="h-4 w-4" /> : <Moon className="h-4 w-4" />}
       </button>
-      <button
-        type="button"
-        className="flex items-center gap-1.5 px-3 py-2 rounded-lg bg-card border border-border hover:bg-muted transition-colors text-sm"
-        title="Language"
-      >
-        <Globe className="h-4 w-4" />
-        English
-      </button>
+      <LanguageSelector />
     </div>
   );
 }

apps/web/src/components/layout/sidebar.tsx

@@ -1,6 +1,7 @@
 import { FolderOpen, Grid3x3, HelpCircle, LayoutGrid, Settings, Workflow } from "lucide-react";
 import type { ComponentType, SVGProps } from "react";
 import { Link, useLocation } from "react-router-dom";
+import { useTranslation } from "@/contexts/i18n-context";
 import { cn } from "@/lib/utils";
 import { ImageEditIcon } from "../common/image-edit-icon";
 import { OtterLogo } from "../common/otter-logo";
@@ -11,18 +12,21 @@ interface SidebarItem {
   href?: string;
 }
 
-const topItems: SidebarItem[] = [
-  { icon: LayoutGrid, label: "Tools", href: "/" },
-  { icon: Grid3x3, label: "Grid", href: "/fullscreen" },
-  { icon: Workflow, label: "Automate", href: "/automate" },
-  { icon: ImageEditIcon, label: "Editor", href: "/editor" },
-  { icon: FolderOpen, label: "Files", href: "/files" },
-];
-
-const bottomItems: SidebarItem[] = [
-  { icon: HelpCircle, label: "Help" },
-  { icon: Settings, label: "Settings" },
-];
+function useNavItems() {
+  const { t } = useTranslation();
+  const topItems: SidebarItem[] = [
+    { icon: LayoutGrid, label: t.sidebar.tools, href: "/" },
+    { icon: Grid3x3, label: t.sidebar.grid, href: "/fullscreen" },
+    { icon: Workflow, label: t.sidebar.automate, href: "/automate" },
+    { icon: ImageEditIcon, label: t.sidebar.editor, href: "/editor" },
+    { icon: FolderOpen, label: t.sidebar.files, href: "/files" },
+  ];
+  const bottomItems: SidebarItem[] = [
+    { icon: HelpCircle, label: t.sidebar.help },
+    { icon: Settings, label: t.sidebar.settings },
+  ];
+  return { topItems, bottomItems };
+}
 
 interface SidebarProps {
   onSettingsClick: () => void;
@@ -40,6 +44,7 @@ export function Sidebar({
   expanded = false,
 }: SidebarProps) {
   const location = useLocation();
+  const { topItems, bottomItems } = useNavItems();
 
   const renderItem = (item: SidebarItem, isActive: boolean) => {
     const content = expanded ? (
@@ -68,14 +73,14 @@ export function Sidebar({
       </div>
     );
 
-    if (item.label === "Settings") {
+    if (item === bottomItems[1]) {
       return (
         <button key={item.label} type="button" onClick={onSettingsClick} className="w-full">
           {content}
         </button>
       );
     }
-    if (item.label === "Help") {
+    if (item === bottomItems[0]) {
       return (
         <button
           key={item.label}

apps/web/src/components/layout/tool-panel.tsx

@@ -1,11 +1,14 @@
 import { CATEGORIES, TOOLS } from "@snapotter/shared";
 import { useEffect, useMemo, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
+import { getCategoryName } from "@/lib/tool-i18n";
 import { useFeaturesStore } from "@/stores/features-store";
 import { useSettingsStore } from "@/stores/settings-store";
 import { SearchBar } from "../common/search-bar";
 import { ToolCard } from "../common/tool-card";
 
 export function ToolPanel() {
+  const { t } = useTranslation();
   const [search, setSearch] = useState("");
   const { disabledTools, experimentalEnabled, loaded, fetch } = useSettingsStore();
   const fetchFeatures = useFeaturesStore((s) => s.fetch);
@@ -54,7 +57,7 @@ export function ToolPanel() {
         {CATEGORIES.filter((cat) => groupedTools.has(cat.id)).map((category) => (
           <div key={category.id} className="mb-4">
             <h3 className="text-xs font-semibold uppercase text-muted-foreground tracking-wider mb-2">
-              {category.name}
+              {getCategoryName(t, category.id, category.name)}
             </h3>
             <div className="space-y-0.5">
               {groupedTools.get(category.id)?.map((tool) => (

apps/web/src/components/settings/ai-features-section.tsx

@@ -1,7 +1,9 @@
 import type { FeatureBundleState } from "@snapotter/shared";
 import { Clock, Download, Loader2, RefreshCw, RotateCcw, Trash2 } from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { apiGet } from "@/lib/api";
+import { format } from "@/lib/format";
 import { useFeaturesStore } from "@/stores/features-store";
 
 function formatBytes(bytes: number): string {
@@ -52,6 +54,7 @@ const PROGRESS_MESSAGES = [
 ];
 
 export function AiFeaturesSection() {
+  const { t } = useTranslation();
   const {
     bundles,
     fetch,
@@ -95,10 +98,8 @@ export function AiFeaturesSection() {
     <div className="space-y-5">
       <div className="flex items-center justify-between">
         <div>
-          <h3 className="text-lg font-semibold text-foreground">AI Features</h3>
-          <p className="text-sm text-muted-foreground mt-1">
-            Manage AI model bundles for advanced image processing.
-          </p>
+          <h3 className="text-lg font-semibold text-foreground">{t.settings.aiFeatures.title}</h3>
+          <p className="text-sm text-muted-foreground mt-1">{t.settings.aiFeatures.description}</p>
         </div>
         <button
           type="button"
@@ -107,7 +108,7 @@ export function AiFeaturesSection() {
           className="flex items-center gap-2 px-4 py-2 rounded-lg bg-primary text-primary-foreground text-sm font-medium hover:bg-primary/90 transition-colors disabled:opacity-50"
         >
           <Download className="h-4 w-4" />
-          Install All
+          {t.settings.aiFeatures.installAll}
         </button>
       </div>
 
@@ -130,7 +131,7 @@ export function AiFeaturesSection() {
 
       {diskUsage !== null && (
         <p className="text-xs text-muted-foreground pt-2 border-t border-border">
-          Disk usage: {formatBytes(diskUsage)}
+          {format(t.settings.aiFeatures.diskUsage, { size: formatBytes(diskUsage) })}
         </p>
       )}
     </div>
@@ -163,6 +164,7 @@ function BundleCard({
   isQueued: boolean;
   startTime: number | null;
 }) {
+  const { t } = useTranslation();
   const [confirming, setConfirming] = useState(false);
   const [messageIndex, setMessageIndex] = useState(() =>
     Math.floor(Math.random() * PROGRESS_MESSAGES.length),
@@ -197,24 +199,30 @@ function BundleCard({
             {bundle.description} (~{bundle.estimatedSize})
           </p>
         </div>
-        <div className="flex items-center gap-3 shrink-0 ml-4">
+        <div className="flex items-center gap-3 shrink-0 ms-4">
           <div className="flex items-center gap-1.5">
             {status === "installed" && (
               <>
                 <span className="bg-green-500 rounded-full h-2 w-2" />
-                <span className="text-xs text-muted-foreground">Installed</span>
+                <span className="text-xs text-muted-foreground">
+                  {t.settings.aiFeatures.installed}
+                </span>
               </>
             )}
             {status === "not_installed" && !error && (
               <>
                 <span className="bg-muted-foreground rounded-full h-2 w-2" />
-                <span className="text-xs text-muted-foreground">Not installed</span>
+                <span className="text-xs text-muted-foreground">
+                  {t.settings.aiFeatures.notInstalled}
+                </span>
               </>
             )}
             {status === "queued" && (
               <>
                 <Clock className="h-3.5 w-3.5 text-muted-foreground" />
-                <span className="text-xs text-muted-foreground">Queued</span>
+                <span className="text-xs text-muted-foreground">
+                  {t.settings.aiFeatures.queued}
+                </span>
               </>
             )}
             {status === "installing" && progress && (
@@ -240,7 +248,7 @@ function BundleCard({
               className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg bg-primary text-primary-foreground text-sm font-medium hover:bg-primary/90 transition-colors"
             >
               <Download className="h-3.5 w-3.5" />
-              Install
+              {t.settings.aiFeatures.install}
             </button>
           )}
           {status === "installed" && !confirming && (
@@ -251,7 +259,7 @@ function BundleCard({
                 className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg border border-border text-sm text-muted-foreground hover:bg-muted transition-colors"
               >
                 <RefreshCw className="h-3.5 w-3.5" />
-                Repair
+                {t.settings.aiFeatures.repair}
               </button>
               <button
                 type="button"
@@ -259,7 +267,7 @@ function BundleCard({
                 className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg border border-border text-sm text-muted-foreground hover:bg-destructive/10 hover:text-destructive transition-colors"
               >
                 <Trash2 className="h-3.5 w-3.5" />
-                Uninstall
+                {t.settings.aiFeatures.uninstall}
               </button>
             </div>
           )}
@@ -274,14 +282,14 @@ function BundleCard({
                 className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg bg-destructive text-destructive-foreground text-sm font-medium hover:bg-destructive/90 transition-colors"
               >
                 <Trash2 className="h-3.5 w-3.5" />
-                Confirm
+                {t.common.confirm}
               </button>
               <button
                 type="button"
                 onClick={() => setConfirming(false)}
                 className="px-3 py-1.5 rounded-lg border border-border text-sm text-muted-foreground hover:bg-muted transition-colors"
               >
-                Cancel
+                {t.common.cancel}
               </button>
             </div>
           )}
@@ -292,7 +300,7 @@ function BundleCard({
               className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg bg-primary text-primary-foreground text-sm font-medium opacity-50"
             >
               <Loader2 className="h-3.5 w-3.5 animate-spin" />
-              Installing...
+              {t.settings.aiFeatures.installing}
             </button>
           )}
           {(status === "error" || error) && !isInstalling && !isQueued && (
@@ -302,7 +310,7 @@ function BundleCard({
               className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg bg-primary text-primary-foreground text-sm font-medium hover:bg-primary/90 transition-colors"
             >
               <RotateCcw className="h-3.5 w-3.5" />
-              Retry
+              {t.common.retry}
             </button>
           )}
         </div>
@@ -319,7 +327,7 @@ function BundleCard({
             <p className="text-xs text-muted-foreground italic">
               {PROGRESS_MESSAGES[messageIndex]}
             </p>
-            {eta && <p className="text-xs text-muted-foreground shrink-0 ml-2">{eta}</p>}
+            {eta && <p className="text-xs text-muted-foreground shrink-0 ms-2">{eta}</p>}
           </div>
         </div>
       )}

apps/web/src/components/tools/ai-canvas-expand-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useCallback, useEffect, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type Tier = "fast" | "balanced" | "high";
@@ -22,6 +24,7 @@ const EXTEND_PRESETS = [
 ];
 
 export function AiCanvasExpandSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const { processFiles, processAllFiles, processing, error, downloadUrl, progress } =
     useToolProcessor("ai-canvas-expand");
@@ -211,7 +214,7 @@ export function AiCanvasExpandSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Extending canvas"
+          label={t.toolSettings["ai-canvas-expand"].progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -223,7 +226,9 @@ export function AiCanvasExpandSettings() {
           disabled={!hasFile || !hasExtension || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Extend (${files.length} files)` : "Extend Canvas"}
+          {files.length > 1
+            ? format(t.toolSettings["ai-canvas-expand"].submitBatch, { count: files.length })
+            : t.toolSettings["ai-canvas-expand"].submit}
         </button>
       )}
 

apps/web/src/components/tools/barcode-read-settings.tsx

@@ -1,7 +1,9 @@
 import { Check, Copy, Download, Search } from "lucide-react";
 import { useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
+import { format } from "@/lib/format";
 import { copyToClipboard } from "@/lib/utils";
 import { useFileStore } from "@/stores/file-store";
 
@@ -106,6 +108,7 @@ function scanOneFile(
 }
 
 export function BarcodeReadSettings() {
+  const { t } = useTranslation();
   const { files, processing, error, setProcessing, setError } = useFileStore();
 
   const [tryHarder, setTryHarder] = useState(false);

apps/web/src/components/tools/beautify-settings.tsx

@@ -858,7 +858,7 @@ export function BeautifyControls({
                       <button
                         type="button"
                         onClick={() => handleRemoveStop(i)}
-                        className="ml-auto p-0.5 rounded hover:bg-muted text-muted-foreground hover:text-foreground"
+                        className="ms-auto p-0.5 rounded hover:bg-muted text-muted-foreground hover:text-foreground"
                       >
                         <X className="h-3 w-3" />
                       </button>

apps/web/src/components/tools/blur-faces-settings.tsx

@@ -1,6 +1,7 @@
 import { Download } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
 import { useFileStore } from "@/stores/file-store";
 
@@ -10,6 +11,7 @@ export interface BlurFacesControlsProps {
 }
 
 export function BlurFacesControls({ settings: initialSettings, onChange }: BlurFacesControlsProps) {
+  const { t } = useTranslation();
   const [blurRadius, setBlurRadius] = useState(30);
   const [sensitivity, setSensitivity] = useState(50);
 
@@ -37,7 +39,7 @@ export function BlurFacesControls({ settings: initialSettings, onChange }: BlurF
       <div>
         <div className="flex justify-between items-center">
           <label htmlFor="blur-faces-blur-radius" className="text-xs text-muted-foreground">
-            Blur Radius
+            {t.toolSettings["blur-faces"].blurRadius}
           </label>
           <span className="text-xs font-mono text-foreground">{blurRadius}</span>
         </div>
@@ -51,8 +53,8 @@ export function BlurFacesControls({ settings: initialSettings, onChange }: BlurF
           className="w-full mt-1"
         />
         <div className="flex justify-between text-[10px] text-muted-foreground mt-0.5">
-          <span>Light</span>
-          <span>Heavy</span>
+          <span>{t.toolSettings["blur-faces"].blurLight}</span>
+          <span>{t.toolSettings["blur-faces"].blurHeavy}</span>
         </div>
       </div>
 
@@ -60,7 +62,7 @@ export function BlurFacesControls({ settings: initialSettings, onChange }: BlurF
       <div>
         <div className="flex justify-between items-center">
           <label htmlFor="blur-faces-sensitivity" className="text-xs text-muted-foreground">
-            Detection Sensitivity
+            {t.toolSettings["blur-faces"].detectionSensitivity}
           </label>
           <span className="text-xs font-mono text-foreground">{sensitivity}%</span>
         </div>
@@ -74,8 +76,8 @@ export function BlurFacesControls({ settings: initialSettings, onChange }: BlurF
           className="w-full mt-1"
         />
         <div className="flex justify-between text-[10px] text-muted-foreground mt-0.5">
-          <span>More faces</span>
-          <span>Fewer faces</span>
+          <span>{t.toolSettings["blur-faces"].moreFaces}</span>
+          <span>{t.toolSettings["blur-faces"].fewerFaces}</span>
         </div>
       </div>
     </div>
@@ -83,6 +85,7 @@ export function BlurFacesControls({ settings: initialSettings, onChange }: BlurF
 }
 
 export function BlurFacesSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -128,7 +131,7 @@ export function BlurFacesSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Blurring faces"
+          label={t.toolSettings["blur-faces"].progressLabel}
           percent={progress.percent}
           elapsed={progress.elapsed}
         />
@@ -153,7 +156,7 @@ export function BlurFacesSettings() {
           className="w-full py-2.5 rounded-lg border border-primary text-primary font-medium flex items-center justify-center gap-2 hover:bg-primary/5"
         >
           <Download className="h-4 w-4" />
-          Download
+          {t.common.download}
         </a>
       )}
     </div>

apps/web/src/components/tools/border-settings.tsx

@@ -2,7 +2,9 @@ import { Download } from "lucide-react";
 import type React from "react";
 import { useCallback, useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 // ── Presets ──────────────────────────────────────────────────────────
@@ -225,6 +227,7 @@ export function BorderControls({
   onChange,
   onImageStyle,
 }: BorderControlsProps) {
+  const { t } = useTranslation();
   const [selectedPreset, setSelectedPreset] = useState<string | null>(null);
   const [borderWidth, setBorderWidth] = useState(10);
   const [borderColor, setBorderColor] = useState("#000000");

apps/web/src/components/tools/bulk-rename-settings.tsx

@@ -1,8 +1,11 @@
 import { Download, Loader2 } from "lucide-react";
 import { useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 export function BulkRenameSettings() {
+  const { t } = useTranslation();
   const { files, processing, error, setProcessing, setError } = useFileStore();
   const [pattern, setPattern] = useState("image-{{index}}");
   const [startIndex, setStartIndex] = useState(1);
@@ -69,7 +72,7 @@ export function BulkRenameSettings() {
     <div className="space-y-4">
       <div>
         <label htmlFor="bulk-rename-pattern" className="text-xs text-muted-foreground">
-          Pattern
+          {t.toolSettings["bulk-rename"].pattern}
         </label>
         <input
           id="bulk-rename-pattern"
@@ -85,7 +88,7 @@ export function BulkRenameSettings() {
 
       <div>
         <label htmlFor="bulk-rename-start-index" className="text-xs text-muted-foreground">
-          Start Index
+          {t.toolSettings["bulk-rename"].startIndex}
         </label>
         <input
           id="bulk-rename-start-index"
@@ -99,7 +102,7 @@ export function BulkRenameSettings() {
 
       {previewNames.length > 0 && (
         <div>
-          <p className="text-xs text-muted-foreground">Preview</p>
+          <p className="text-xs text-muted-foreground">{t.toolSettings["bulk-rename"].preview}</p>
           <div className="mt-1 space-y-0.5">
             {previewNames.map((name) => (
               <div
@@ -126,12 +129,14 @@ export function BulkRenameSettings() {
         className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
       >
         {processing && <Loader2 className="h-4 w-4 animate-spin" />}
-        {processing ? "Renaming..." : `Rename ${files.length} Files`}
+        {processing
+          ? t.toolSettings["bulk-rename"].renaming
+          : format(t.toolSettings["bulk-rename"].submit, { count: files.length })}
       </button>
 
       {downloadReady && (
         <p className="text-xs text-green-600 flex items-center gap-1">
-          <Download className="h-3 w-3" /> ZIP downloaded successfully
+          <Download className="h-3 w-3" /> {t.toolSettings["bulk-rename"].zipDownloaded}
         </p>
       )}
     </div>

apps/web/src/components/tools/collage-preview.tsx

@@ -24,6 +24,7 @@ import {
 } from "lucide-react";
 import { type DragEvent, useCallback, useEffect, useRef, useState } from "react";
 import { isImageFile } from "@/components/common/dropzone";
+import { useTranslation } from "@/contexts/i18n-context";
 import { type CollageTemplate, getTemplateById } from "@/lib/collage-templates";
 import { cn } from "@/lib/utils";
 import type { CellTransform, CollageImage } from "@/stores/collage-store";
@@ -50,6 +51,7 @@ function displayUrl(img: CollageImage): string {
 }
 
 export function CollagePreview() {
+  const { t } = useTranslation();
   const images = useCollageStore((s) => s.images);
   const templateId = useCollageStore((s) => s.templateId);
   const phase = useCollageStore((s) => s.phase);
@@ -570,7 +572,7 @@ function CollageCell({
             onChange={handleZoomSlider}
             className="flex-1 h-1.5 accent-white cursor-pointer"
           />
-          <span className="text-white text-xs font-mono w-8 text-right shrink-0">
+          <span className="text-white text-xs font-mono w-8 text-end shrink-0">
             {transform.zoom.toFixed(1)}x
           </span>
           <button

apps/web/src/components/tools/collage-settings.tsx

@@ -1,6 +1,7 @@
 import { Download, Loader2 } from "lucide-react";
 import { useCallback } from "react";
 import { CollapsibleSection } from "@/components/common/collapsible-section";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
 import {
   COLLAGE_TEMPLATES,
@@ -37,6 +38,7 @@ const BG_PRESETS = [
 ];
 
 export function CollageSettings() {
+  const { t } = useTranslation();
   const store = useCollageStore();
   const {
     images,

apps/web/src/components/tools/color-blindness-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 const SIMULATION_TYPES = [
@@ -65,6 +67,7 @@ const SIMULATION_TYPES = [
 const TYPE_MAP = new Map(SIMULATION_TYPES.flatMap((g) => g.types.map((t) => [t.value, t])));
 
 export function ColorBlindnessSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -95,7 +98,7 @@ export function ColorBlindnessSettings() {
     <div className="space-y-4">
       <div>
         <label htmlFor="cb-simulation-type" className="text-xs text-muted-foreground">
-          Simulation Type
+          {t.toolSettings["color-blindness"].simulationType}
         </label>
         <select
           id="cb-simulation-type"
@@ -131,7 +134,7 @@ export function ColorBlindnessSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Simulating color blindness"
+          label={t.toolSettings["color-blindness"].progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -144,7 +147,9 @@ export function ColorBlindnessSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Simulate (${files.length} files)` : "Simulate"}
+          {files.length > 1
+            ? format(t.toolSettings["color-blindness"].submitBatch, { count: files.length })
+            : t.toolSettings["color-blindness"].submit}
         </button>
       )}
 
@@ -156,7 +161,7 @@ export function ColorBlindnessSettings() {
           className="w-full py-2.5 rounded-lg border border-primary text-primary font-medium flex items-center justify-center gap-2 hover:bg-primary/5"
         >
           <Download className="h-4 w-4" />
-          Download
+          {t.common.download}
         </a>
       )}
     </div>

apps/web/src/components/tools/color-palette-settings.tsx

@@ -1,9 +1,11 @@
 import { Check, Copy, Loader2 } from "lucide-react";
 import { useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
 import { copyToClipboard } from "@/lib/utils";
 import { useFileStore } from "@/stores/file-store";
 export function ColorPaletteSettings() {
+  const { t } = useTranslation();
   const { files, processing, error, setProcessing, setError } = useFileStore();
   const [colors, setColors] = useState<string[]>([]);
   const [copiedIdx, setCopiedIdx] = useState<number | null>(null);
@@ -81,7 +83,7 @@ export function ColorPaletteSettings() {
                   className="w-6 h-6 rounded border border-border shrink-0"
                   style={{ backgroundColor: color }}
                 />
-                <span className="text-xs font-mono text-foreground flex-1 text-left">{color}</span>
+                <span className="text-xs font-mono text-foreground flex-1 text-start">{color}</span>
                 {copiedIdx === i ? (
                   <Check className="h-3 w-3 text-green-500 shrink-0" />
                 ) : (

apps/web/src/components/tools/color-settings.tsx

@@ -275,10 +275,10 @@ export function ColorControls({
       >
         {channelsOpen ? <ChevronDown className="h-3 w-3" /> : <ChevronRight className="h-3 w-3" />}
         Color Channels
-        {hasChannelChanges && <span className="ml-auto text-primary text-[10px]">modified</span>}
+        {hasChannelChanges && <span className="ms-auto text-primary text-[10px]">modified</span>}
       </button>
       {channelsOpen && (
-        <div className="space-y-2 pl-1">
+        <div className="space-y-2 ps-1">
           <SliderControl
             label="Red"
             value={red}
@@ -457,11 +457,9 @@ function SliderControl({
       <div className="flex justify-between items-center">
         <label htmlFor={id} className={`text-xs ${color || "text-muted-foreground"}`}>
           {label}
-          {hint && <span className="text-[10px] text-muted-foreground/60 ml-1">({hint})</span>}
+          {hint && <span className="text-[10px] text-muted-foreground/60 ms-1">({hint})</span>}
         </label>
-        <span className="text-xs font-mono text-foreground tabular-nums w-8 text-right">
-          {value}
-        </span>
+        <span className="text-xs font-mono text-foreground tabular-nums w-8 text-end">{value}</span>
       </div>
       <input
         id={id}

apps/web/src/components/tools/colorize-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type Model = "auto" | "ddcolor" | "opencv";
@@ -13,6 +15,7 @@ const MODEL_OPTIONS: { value: Model; label: string; desc: string }[] = [
 ];
 
 export function ColorizeSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -83,7 +86,7 @@ export function ColorizeSettings() {
                   ? "Natural"
                   : "Vivid"}
           </span>
-          <span className="text-xs font-mono text-foreground tabular-nums w-10 text-right">
+          <span className="text-xs font-mono text-foreground tabular-nums w-10 text-end">
             {intensity}%
           </span>
         </div>
@@ -126,7 +129,9 @@ export function ColorizeSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {hasMultiple ? `Colorize (${files.length} files)` : "Colorize"}
+          {hasMultiple
+            ? format(t.toolSettings.colorize.submitBatch, { count: files.length })
+            : t.toolSettings.colorize.submit}
         </button>
       )}
 

apps/web/src/components/tools/compare-settings.tsx

@@ -1,8 +1,10 @@
 import { Download, Loader2, Upload } from "lucide-react";
 import { useRef, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
 import { useFileStore } from "@/stores/file-store";
 export function CompareSettings() {
+  const { t } = useTranslation();
   const { files, processing, error, setProcessing, setError, setProcessedUrl } = useFileStore();
   const [secondFile, setSecondFile] = useState<File | null>(null);
   const [similarity, setSimilarity] = useState<number | null>(null);

apps/web/src/components/tools/compose-settings.tsx

@@ -1,8 +1,10 @@
 import { Download, Loader2, Upload } from "lucide-react";
 import { useRef, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
 import { useFileStore } from "@/stores/file-store";
 export function ComposeSettings() {
+  const { t } = useTranslation();
   const { files, processing, error, setProcessing, setError, setProcessedUrl, setSizes, setJobId } =
     useFileStore();
   const [overlayFile, setOverlayFile] = useState<File | null>(null);
@@ -166,7 +168,7 @@ export function ComposeSettings() {
         className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
       >
         {processing && <Loader2 className="h-4 w-4 animate-spin" />}
-        {processing ? "Processing..." : "Compose"}
+        {processing ? "Processing..." : t.toolSettings.compose.submit}
       </button>
 
       {downloadUrl && (

apps/web/src/components/tools/compress-settings.tsx

@@ -1,7 +1,9 @@
 import { Download, Minus, Plus } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type CompressMode = "quality" | "targetSize";
@@ -13,6 +15,7 @@ export interface CompressControlsProps {
 }
 
 export function CompressControls({ settings: initialSettings, onChange }: CompressControlsProps) {
+  const { t } = useTranslation();
   const [mode, setMode] = useState<CompressMode>("targetSize");
   const [quality, setQuality] = useState(75);
   const [targetSizeValue, setTargetSizeValue] = useState("");
@@ -47,21 +50,23 @@ export function CompressControls({ settings: initialSettings, onChange }: Compre
     <div className="space-y-4">
       {/* Mode toggle */}
       <div>
-        <p className="text-sm font-medium text-muted-foreground">Compression Mode</p>
+        <p className="text-sm font-medium text-muted-foreground">
+          {t.toolSettings.compress.compressionMode}
+        </p>
         <div className="flex gap-1 mt-1">
           <button
             type="button"
             onClick={() => setMode("targetSize")}
             className={`flex-1 text-xs py-1.5 rounded ${mode === "targetSize" ? "bg-primary text-primary-foreground" : "bg-muted text-muted-foreground"}`}
           >
-            Target Size
+            {t.toolSettings.compress.targetSize}
           </button>
           <button
             type="button"
             onClick={() => setMode("quality")}
             className={`flex-1 text-xs py-1.5 rounded ${mode === "quality" ? "bg-primary text-primary-foreground" : "bg-muted text-muted-foreground"}`}
           >
-            Quality
+            {t.toolSettings.compress.quality}
           </button>
         </div>
       </div>
@@ -69,7 +74,7 @@ export function CompressControls({ settings: initialSettings, onChange }: Compre
       {mode === "targetSize" ? (
         <div>
           <label htmlFor="compress-target-size" className="text-xs text-muted-foreground">
-            Target Size
+            {t.toolSettings.compress.targetSize}
           </label>
           <div className="flex gap-1.5 mt-0.5">
             <input
@@ -127,8 +132,8 @@ export function CompressControls({ settings: initialSettings, onChange }: Compre
             </button>
           </div>
           <div className="flex justify-between text-[10px] text-muted-foreground mt-0.5">
-            <span>Smallest file</span>
-            <span>Best quality</span>
+            <span>{t.toolSettings.compress.smallestFile}</span>
+            <span>{t.toolSettings.compress.bestQuality}</span>
           </div>
         </div>
       )}
@@ -137,6 +142,7 @@ export function CompressControls({ settings: initialSettings, onChange }: Compre
 }
 
 export function CompressSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -178,10 +184,17 @@ export function CompressSettings() {
       {/* Size info */}
       {originalSize != null && processedSize != null && (
         <div className="text-xs text-muted-foreground space-y-0.5">
-          <p>Original: {(originalSize / 1024).toFixed(1)} KB</p>
-          <p>Processed: {(processedSize / 1024).toFixed(1)} KB</p>
+          <p>
+            {format(t.toolSettings.compress.original, { size: (originalSize / 1024).toFixed(1) })}
+          </p>
+          <p>
+            {format(t.toolSettings.compress.processed, { size: (processedSize / 1024).toFixed(1) })}
+          </p>
           <p className="font-medium text-foreground">
-            Saved: {originalSize > 0 ? ((1 - processedSize / originalSize) * 100).toFixed(1) : "0"}%
+            {format(t.toolSettings.compress.saved, {
+              percent:
+                originalSize > 0 ? ((1 - processedSize / originalSize) * 100).toFixed(1) : "0",
+            })}
           </p>
         </div>
       )}
@@ -191,7 +204,7 @@ export function CompressSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Compressing"
+          label={t.toolSettings.compress.progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -203,7 +216,9 @@ export function CompressSettings() {
           disabled={!hasFile || !canProcess || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Compress (${files.length} files)` : "Compress"}
+          {files.length > 1
+            ? format(t.toolSettings.compress.submitBatch, { count: files.length })
+            : t.toolSettings.compress.submit}
         </button>
       )}
 
@@ -216,7 +231,7 @@ export function CompressSettings() {
           className="w-full py-2.5 rounded-lg border border-primary text-primary font-medium flex items-center justify-center gap-2 hover:bg-primary/5"
         >
           <Download className="h-4 w-4" />
-          Download
+          {t.common.download}
         </a>
       )}
     </form>

apps/web/src/components/tools/content-aware-resize-settings.tsx

@@ -1,7 +1,9 @@
 import { Download, Info } from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 function HintIcon({ text }: { text: string }) {
@@ -162,6 +164,7 @@ export function ContentAwareResizeControls({
 }
 
 export function ContentAwareResizeSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const { processFiles, processAllFiles, processing, error, downloadUrl, progress } =
     useToolProcessor("content-aware-resize");
@@ -200,7 +203,7 @@ export function ContentAwareResizeSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Content-aware resizing"
+          label={t.toolSettings["content-aware-resize"].progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -212,7 +215,9 @@ export function ContentAwareResizeSettings() {
           disabled={!canProcess}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Resize (${files.length} files)` : "Resize"}
+          {files.length > 1
+            ? format(t.toolSettings["content-aware-resize"].submitBatch, { count: files.length })
+            : t.toolSettings["content-aware-resize"].submit}
         </button>
       )}
 

apps/web/src/components/tools/convert-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 const OUTPUT_FORMATS = [
@@ -43,6 +45,7 @@ export interface ConvertControlsProps {
 }
 
 export function ConvertControls({ settings: initialSettings, onChange }: ConvertControlsProps) {
+  const { t } = useTranslation();
   const [format, setFormat] = useState<string>("png");
   const [quality, setQuality] = useState(85);
 
@@ -74,7 +77,7 @@ export function ConvertControls({ settings: initialSettings, onChange }: Convert
       {/* Target format */}
       <div>
         <label htmlFor="convert-target-format" className="text-xs text-muted-foreground">
-          Target Format
+          {t.toolSettings.convert.targetFormat}
         </label>
         <select
           id="convert-target-format"
@@ -115,6 +118,7 @@ export function ConvertControls({ settings: initialSettings, onChange }: Convert
 }
 
 export function ConvertSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -154,7 +158,7 @@ export function ConvertSettings() {
       {/* Source format */}
       {hasFile && (
         <div>
-          <p className="text-xs text-muted-foreground">Source Format</p>
+          <p className="text-xs text-muted-foreground">{t.toolSettings.convert.sourceFormat}</p>
           <div className="mt-0.5 px-2 py-1.5 rounded bg-muted text-sm text-foreground uppercase font-mono">
             {sourceExt}
           </div>
@@ -179,7 +183,7 @@ export function ConvertSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Converting"
+          label={t.toolSettings.convert.progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -191,7 +195,9 @@ export function ConvertSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Convert (${files.length} files)` : "Convert"}
+          {files.length > 1
+            ? format(t.toolSettings.convert.submitBatch, { count: files.length })
+            : t.toolSettings.convert.submit}
         </button>
       )}
 
@@ -204,7 +210,7 @@ export function ConvertSettings() {
           className="w-full py-2.5 rounded-lg border border-primary text-primary font-medium flex items-center justify-center gap-2 hover:bg-primary/5"
         >
           <Download className="h-4 w-4" />
-          Download
+          {t.common.download}
         </a>
       )}
     </form>

apps/web/src/components/tools/crop-settings.tsx

@@ -2,7 +2,9 @@ import { ArrowLeftRight, Download, Grid3x3 } from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
 import type { Crop } from "react-image-crop";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 const ASPECT_PRESETS = [
@@ -34,6 +36,7 @@ export function CropSettings({
   onAspectChange,
   onGridToggle,
 }: CropSettingsProps) {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const { processFiles, processAllFiles, processing, error, downloadUrl, progress } =
     useToolProcessor("crop");
@@ -216,7 +219,7 @@ export function CropSettings({
       {/* Aspect Ratio */}
       <div>
         <div className="flex items-center justify-between mb-1">
-          <p className="text-xs text-muted-foreground">Aspect Ratio</p>
+          <p className="text-xs text-muted-foreground">{t.toolSettings.crop.aspectRatio}</p>
           {aspect !== undefined && (
             <button
               type="button"
@@ -288,7 +291,7 @@ export function CropSettings({
 
       {/* Position & Size */}
       <div>
-        <p className="text-xs text-muted-foreground">Position & Size</p>
+        <p className="text-xs text-muted-foreground">{t.toolSettings.crop.positionAndSize}</p>
         <div className="grid grid-cols-2 gap-2 mt-1">
           <div>
             <label htmlFor="crop-x" className="text-[10px] text-muted-foreground">
@@ -358,7 +361,7 @@ export function CropSettings({
           className="accent-primary h-3.5 w-3.5"
         />
         <Grid3x3 className="h-3.5 w-3.5" />
-        Rule of Thirds
+        {t.toolSettings.crop.ruleOfThirds}
       </label>
 
       {/* Error */}
@@ -369,7 +372,7 @@ export function CropSettings({
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Cropping"
+          label={t.toolSettings.crop.progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -381,7 +384,9 @@ export function CropSettings({
           disabled={!canSubmit}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Crop (${files.length} files)` : "Crop"}
+          {files.length > 1
+            ? format(t.toolSettings.crop.submitBatch, { count: files.length })
+            : t.toolSettings.crop.submit}
         </button>
       )}
 
@@ -394,7 +399,7 @@ export function CropSettings({
           className="w-full py-2.5 rounded-lg border border-primary text-primary font-medium flex items-center justify-center gap-2 hover:bg-primary/5"
         >
           <Download className="h-4 w-4" />
-          Download
+          {t.common.download}
         </a>
       )}
     </form>
@@ -409,6 +414,7 @@ export interface CropControlsProps {
 }
 
 export function CropControls({ settings: initialSettings, onChange }: CropControlsProps) {
+  const { t } = useTranslation();
   const [left, setLeft] = useState(0);
   const [top, setTop] = useState(0);
   const [width, setWidth] = useState("");
@@ -443,7 +449,7 @@ export function CropControls({ settings: initialSettings, onChange }: CropContro
       <div className="grid grid-cols-2 gap-2">
         <div>
           <label htmlFor="pipeline-crop-left" className="text-xs text-muted-foreground">
-            Left offset (px)
+            {t.toolSettings.crop.leftOffsetPx}
           </label>
           <input
             id="pipeline-crop-left"
@@ -456,7 +462,7 @@ export function CropControls({ settings: initialSettings, onChange }: CropContro
         </div>
         <div>
           <label htmlFor="pipeline-crop-top" className="text-xs text-muted-foreground">
-            Top offset (px)
+            {t.toolSettings.crop.topOffsetPx}
           </label>
           <input
             id="pipeline-crop-top"

apps/web/src/components/tools/edit-metadata-settings.tsx

@@ -776,7 +776,7 @@ export function EditMetadataSettings() {
                   <button
                     type="button"
                     onClick={() => loadTemplate(t.name)}
-                    className="flex-1 text-left text-xs px-2 py-1 rounded-md border border-input hover:bg-muted/50 truncate"
+                    className="flex-1 text-start text-xs px-2 py-1 rounded-md border border-input hover:bg-muted/50 truncate"
                   >
                     {t.name}
                   </button>

apps/web/src/components/tools/enhance-faces-settings.tsx

@@ -110,7 +110,7 @@ export function EnhanceFacesControls({
             />
             <span className="text-sm text-foreground">Only enhance main face</span>
           </label>
-          <p className="text-[11px] text-muted-foreground/70 ml-6 mt-0.5">
+          <p className="text-[11px] text-muted-foreground/70 ms-6 mt-0.5">
             For portraits - ignores background faces
           </p>
         </div>

apps/web/src/components/tools/erase-object-settings.tsx

@@ -1,7 +1,9 @@
 import { Download, Redo, Trash2 } from "lucide-react";
 import { useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
+import { format } from "@/lib/format";
 import { generateId } from "@/lib/utils";
 import { useFileStore } from "@/stores/file-store";
 import type { EraserCanvasRef } from "./eraser-canvas";
@@ -36,6 +38,7 @@ export function EraseObjectSettings({
   onMaskCenter,
   maskedFileCount,
 }: EraseObjectSettingsProps) {
+  const { t } = useTranslation();
   const {
     files,
     entries,
@@ -386,7 +389,7 @@ export function EraseObjectSettings({
       <div>
         <div className="flex justify-between items-center">
           <label htmlFor="eraser-brush-size" className="text-xs text-muted-foreground">
-            Brush Size
+            {t.toolSettings["erase-object"].brushSize}
           </label>
           <span className="text-xs font-mono text-foreground">{brushSize}px</span>
         </div>
@@ -400,8 +403,8 @@ export function EraseObjectSettings({
           className="w-full mt-1"
         />
         <div className="flex justify-between text-[10px] text-muted-foreground mt-0.5">
-          <span>Fine</span>
-          <span>Wide</span>
+          <span>{t.toolSettings["erase-object"].fine}</span>
+          <span>{t.toolSettings["erase-object"].wide}</span>
         </div>
       </div>
 
@@ -493,7 +496,7 @@ export function EraseObjectSettings({
         <ProgressCard
           active={processing}
           phase={progressPhase === "idle" ? "uploading" : progressPhase}
-          label={progressStage || "Erasing object"}
+          label={progressStage || t.toolSettings["erase-object"].progressLabel}
           percent={progressPercent}
           elapsed={elapsed}
         />
@@ -505,7 +508,9 @@ export function EraseObjectSettings({
           disabled={!hasFile || (!hasStrokes && maskedFileCount === 0) || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {maskedFileCount > 1 ? `Erase All (${maskedFileCount})` : "Erase Object"}
+          {maskedFileCount > 1
+            ? format(t.toolSettings["erase-object"].submitBatch, { count: maskedFileCount })
+            : t.toolSettings["erase-object"].submit}
         </button>
       )}
 

apps/web/src/components/tools/favicon-settings.tsx

@@ -2,7 +2,9 @@ import { Download } from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
 import { flushSync } from "react-dom";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 const SIZES = [
@@ -16,6 +18,7 @@ const SIZES = [
 ];
 
 export function FaviconSettings() {
+  const { t } = useTranslation();
   const { files, error, setProcessing, setError } = useFileStore();
   const [downloadUrl, setDownloadUrl] = useState<string | null>(null);
   const [busy, setBusy] = useState(false);
@@ -128,13 +131,14 @@ export function FaviconSettings() {
   return (
     <div className="space-y-4">
       <p className="text-xs text-muted-foreground">
-        Upload square images (recommended 512x512 or larger) to generate all favicon and app icon
-        sizes.{" "}
-        {files.length > 1 && `Each of the ${files.length} images gets its own folder in the ZIP.`}
+        {t.toolSettings.favicon.uploadHint}{" "}
+        {files.length > 1 && format(t.toolSettings.favicon.multipleHint, { count: files.length })}
       </p>
 
       <div>
-        <p className="text-xs font-medium text-muted-foreground">Generated Sizes (per image)</p>
+        <p className="text-xs font-medium text-muted-foreground">
+          {t.toolSettings.favicon.generatedSizes}
+        </p>
         <div className="mt-1 space-y-0.5">
           {SIZES.map((s) => (
             <div key={s.name} className="flex justify-between text-xs text-foreground">
@@ -143,7 +147,9 @@ export function FaviconSettings() {
             </div>
           ))}
         </div>
-        <p className="text-[10px] text-muted-foreground mt-1">+ manifest.json + HTML snippet</p>
+        <p className="text-[10px] text-muted-foreground mt-1">
+          {t.toolSettings.favicon.plusManifest}
+        </p>
       </div>
 
       {error && <p className="text-xs text-red-500">{error}</p>}
@@ -152,7 +158,7 @@ export function FaviconSettings() {
         <ProgressCard
           active={busy}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Generating Favicons"
+          label={t.toolSettings.favicon.progressLabel}
           stage={
             progress.phase === "uploading"
               ? "Uploading images..."
@@ -169,7 +175,9 @@ export function FaviconSettings() {
           disabled={!hasFiles || busy}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          Generate Favicons ({files.length} image{files.length !== 1 ? "s" : ""})
+          {files.length !== 1
+            ? format(t.toolSettings.favicon.submitPlural, { count: files.length })
+            : format(t.toolSettings.favicon.submit, { count: files.length })}
         </button>
       )}
 

apps/web/src/components/tools/find-duplicates-results.tsx

@@ -1,4 +1,5 @@
 import { ArrowLeft, ChevronLeft, ChevronRight, Crown, Search } from "lucide-react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatFileSize } from "@/lib/download";
 import type { DuplicateFileInfo } from "@/stores/duplicate-store";
 import { useDuplicateStore } from "@/stores/duplicate-store";
@@ -63,7 +64,7 @@ function OverviewGrid() {
             key={group.groupId}
             type="button"
             onClick={() => setSelectedGroup(gi)}
-            className="w-full text-left p-3 rounded-lg bg-muted/50 border border-border hover:border-primary/50 transition-colors"
+            className="w-full text-start p-3 rounded-lg bg-muted/50 border border-border hover:border-primary/50 transition-colors"
           >
             <div className="flex justify-between items-center mb-2.5">
               <div className="flex items-center gap-2">
@@ -190,7 +191,7 @@ function DetailComparison() {
               key={file.filename}
               type="button"
               onClick={() => overrideBest(selectedGroupIndex, fi)}
-              className="text-left"
+              className="text-start"
               title={isCurrentBest ? "Selected as best" : "Click to mark as best"}
             >
               <div
@@ -219,18 +220,16 @@ function DetailComparison() {
                 <p className="font-medium text-foreground truncate">{file.filename}</p>
                 <div className="grid grid-cols-2 gap-x-4 gap-y-1">
                   <span className="text-muted-foreground">Dimensions</span>
-                  <span className="text-foreground text-right">
+                  <span className="text-foreground text-end">
                     {file.width} x {file.height}
                   </span>
                   <span className="text-muted-foreground">File size</span>
-                  <span className="text-foreground text-right">
-                    {formatFileSize(file.fileSize)}
-                  </span>
+                  <span className="text-foreground text-end">{formatFileSize(file.fileSize)}</span>
                   <span className="text-muted-foreground">Format</span>
-                  <span className="text-foreground text-right">{file.format.toUpperCase()}</span>
+                  <span className="text-foreground text-end">{file.format.toUpperCase()}</span>
                   <span className="text-muted-foreground">Similarity</span>
                   <span
-                    className={`text-right font-medium ${file.similarity === 100 ? "text-green-500" : "text-yellow-500"}`}
+                    className={`text-end font-medium ${file.similarity === 100 ? "text-green-500" : "text-yellow-500"}`}
                   >
                     {file.similarity}%
                   </span>
@@ -252,6 +251,7 @@ function DetailComparison() {
 }
 
 export function FindDuplicatesResults() {
+  const { t } = useTranslation();
   const { results, scanning, viewMode } = useDuplicateStore();
 
   if (scanning) {

apps/web/src/components/tools/find-duplicates-settings.tsx

@@ -1,5 +1,6 @@
 import { Download, FolderArchive, Loader2 } from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
 import { formatFileSize } from "@/lib/download";
 import type { DuplicateResult } from "@/stores/duplicate-store";
@@ -15,6 +16,7 @@ const PRESET_DESCRIPTIONS: Record<Preset, string> = {
 };
 
 export function FindDuplicatesSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     results,

apps/web/src/components/tools/gif-tools-settings.tsx

@@ -1,8 +1,10 @@
 import { Download, FlipHorizontal2, FlipVertical2, Link, RotateCw, Unlink } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useGifInfo } from "@/hooks/use-gif-info";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type GifMode = "resize" | "optimize" | "speed" | "reverse" | "extract" | "rotate";
@@ -25,6 +27,7 @@ export interface GifToolsControlsProps {
 }
 
 export function GifToolsControls({ settings: initialSettings, onChange }: GifToolsControlsProps) {
+  const { t } = useTranslation();
   const { info, loading: infoLoading } = useGifInfo();
   const isAnimated = (info?.pages ?? 0) > 1;
 
@@ -643,6 +646,7 @@ export function GifToolsControls({ settings: initialSettings, onChange }: GifToo
 }
 
 export function GifToolsSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -678,7 +682,7 @@ export function GifToolsSettings() {
           <p>
             Processed: {(processedSize / 1024).toFixed(1)} KB
             {originalSize > 0 && (
-              <span className="ml-1">
+              <span className="ms-1">
                 ({Math.round(((processedSize - originalSize) / originalSize) * 100)}%)
               </span>
             )}
@@ -690,7 +694,7 @@ export function GifToolsSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Processing GIF"
+          label={t.toolSettings["gif-tools"].progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -703,7 +707,9 @@ export function GifToolsSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Process (${files.length} files)` : "Process"}
+          {files.length > 1
+            ? format(t.toolSettings["gif-tools"].submitBatch, { count: files.length })
+            : "Process"}
         </button>
       )}
 

apps/web/src/components/tools/image-enhancement-settings.tsx

@@ -11,7 +11,9 @@ import {
 } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type EnhancementMode = "auto" | "portrait" | "landscape" | "low-light" | "food" | "document";
@@ -144,6 +146,7 @@ export function ImageEnhancementControls({
   onChange,
   onPreviewFilter,
 }: ImageEnhancementControlsProps) {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const [mode, setMode] = useState<EnhancementMode>("auto");
   const [intensity, setIntensity] = useState(50);
@@ -283,7 +286,7 @@ export function ImageEnhancementControls({
 
       {/* Mode selector */}
       <p className="text-[11px] font-semibold uppercase tracking-wider text-muted-foreground/70">
-        Enhancement Mode
+        {t.toolSettings.imageEnhancement.enhancementMode}
       </p>
       <div className="grid grid-cols-3 gap-1">
         {MODES.map(({ value, label, icon: Icon }) => (
@@ -307,7 +310,7 @@ export function ImageEnhancementControls({
       <div className="pt-1">
         <div className="flex justify-between items-center">
           <p className="text-[11px] font-semibold uppercase tracking-wider text-muted-foreground/70">
-            Intensity
+            {t.toolSettings.imageEnhancement.intensity}
           </p>
           <span className="text-xs font-mono text-foreground tabular-nums">{intensity}%</span>
         </div>
@@ -326,7 +329,7 @@ export function ImageEnhancementControls({
         <div className="flex items-center gap-2">
           <Wand2 className="h-3.5 w-3.5 text-muted-foreground" />
           <div>
-            <p className="text-xs font-medium">Deep Enhance (AI)</p>
+            <p className="text-xs font-medium">{t.toolSettings.imageEnhancement.deepEnhance}</p>
             <p className="text-[10px] text-muted-foreground">
               Removes noise and artifacts using AI
             </p>
@@ -358,7 +361,7 @@ export function ImageEnhancementControls({
       {analysis && !analyzing && (
         <div className="space-y-2">
           <p className="text-[11px] font-semibold uppercase tracking-wider text-muted-foreground/70">
-            Detected Issues
+            {t.toolSettings.imageEnhancement.detectedIssues}
           </p>
           {analysis.issues.length === 0 ? (
             <p className="text-xs text-muted-foreground">

apps/web/src/components/tools/image-to-base64-results.tsx

@@ -1,5 +1,6 @@
 import { Check, ClipboardCopy, Download, FileJson, FileText, Loader2 } from "lucide-react";
 import { useCallback, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import type { Base64Result } from "@/stores/base64-store";
 import { useBase64Store } from "@/stores/base64-store";
 import { useFileStore } from "@/stores/file-store";
@@ -168,6 +169,7 @@ function FileResult({ result }: { result: Base64Result }) {
 // -- Main ResultsPanel ------------------------------------------------------
 
 export function ImageToBase64Results() {
+  const { t } = useTranslation();
   const { results, errors, processing, progress } = useBase64Store();
   const { entries, selectedIndex, originalBlobUrl, selectedFileName } = useFileStore();
 

apps/web/src/components/tools/image-to-base64-settings.tsx

@@ -1,6 +1,8 @@
 import { Loader2 } from "lucide-react";
 import { useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
+import { format } from "@/lib/format";
 import { useBase64Store } from "@/stores/base64-store";
 import { useFileStore } from "@/stores/file-store";
 
@@ -14,6 +16,7 @@ const OUTPUT_FORMATS = [
 ] as const;
 
 export function ImageToBase64Settings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const { processing, setProcessing, setProgress, addResult, addError, reset } = useBase64Store();
 

apps/web/src/components/tools/info-settings.tsx

@@ -1,5 +1,6 @@
 import { Loader2 } from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
 import { useFileStore } from "@/stores/file-store";
 
@@ -31,6 +32,7 @@ interface ImageInfoData {
 }
 
 export function InfoSettings() {
+  const { t } = useTranslation();
   const { files, processing, error, setProcessing, setError } = useFileStore();
   const selectedIndex = useFileStore((s) => s.selectedIndex);
   const [info, setInfo] = useState<ImageInfoData | null>(null);

apps/web/src/components/tools/meme-generator-preview.tsx

@@ -163,7 +163,7 @@ function TemplateGallery() {
             value={searchQuery}
             onChange={(e) => setSearchQuery(e.target.value)}
             placeholder="Search templates..."
-            className={cn(INPUT_CLASS, "pl-8")}
+            className={cn(INPUT_CLASS, "ps-8")}
           />
         </div>
 
@@ -183,7 +183,7 @@ function TemplateGallery() {
               )}
             >
               {cat.label}
-              <span className="ml-1 opacity-70">({categoryCounts[cat.id] ?? 0})</span>
+              <span className="ms-1 opacity-70">({categoryCounts[cat.id] ?? 0})</span>
             </button>
           ))}
         </div>
@@ -281,7 +281,7 @@ function LayoutPicker() {
               data-testid={`layout-${key}`}
               onClick={() => setCustomLayout(key)}
               className={cn(
-                "relative rounded-lg border-2 p-3 transition-all text-left",
+                "relative rounded-lg border-2 p-3 transition-all text-start",
                 selected === key
                   ? "border-primary bg-primary/5"
                   : "border-border hover:border-primary/40",

apps/web/src/components/tools/meme-generator-settings.tsx

@@ -8,6 +8,7 @@ import {
   Sparkles,
 } from "lucide-react";
 import { useCallback } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { cn } from "@/lib/utils";
 import {
   FONT_OPTIONS,
@@ -327,6 +328,7 @@ function ResultSettings() {
 // ── Main Settings Component ─────────────────────────────────────────
 
 export function MemeGeneratorSettings() {
+  const { t } = useTranslation();
   const phase = useMemeStore((s) => s.phase);
 
   if (phase === "gallery") return <GallerySettings />;

apps/web/src/components/tools/noise-removal-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type Tier = "quick" | "balanced" | "quality" | "maximum";
@@ -203,6 +205,7 @@ export function NoiseRemovalControls({
 }
 
 export function NoiseRemovalSettings() {
+  const { t } = useTranslation();
   const { files, entries } = useFileStore();
   const {
     processFiles,
@@ -271,7 +274,9 @@ export function NoiseRemovalSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {hasMultiple ? `Remove Noise (${files.length} files)` : "Remove Noise"}
+          {hasMultiple
+            ? format(t.toolSettings["noise-removal"].submitBatch, { count: files.length })
+            : t.toolSettings["noise-removal"].submit}
         </button>
       )}
 

apps/web/src/components/tools/ocr-settings.tsx

@@ -1,7 +1,9 @@
 import { Check, ChevronDown, ChevronRight, Copy, Download, Info } from "lucide-react";
 import { useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
+import { format } from "@/lib/format";
 import { copyToClipboard, generateId } from "@/lib/utils";
 import { useFileStore } from "@/stores/file-store";
 
@@ -100,6 +102,7 @@ function ocrOneFile(
 }
 
 export function OcrSettings() {
+  const { t } = useTranslation();
   const { files, processing, error, setProcessing, setError } = useFileStore();
 
   const [quality, setQuality] = useState<OcrQuality>("balanced");
@@ -219,7 +222,7 @@ export function OcrSettings() {
   return (
     <div className="space-y-3">
       {/* Quality selector */}
-      <SectionLabel>Quality</SectionLabel>
+      <SectionLabel>{t.toolSettings.ocr.quality}</SectionLabel>
       <div className="grid grid-cols-3 gap-1.5">
         {QUALITY_OPTIONS.map((opt) => (
           <button
@@ -245,7 +248,9 @@ export function OcrSettings() {
           onChange={(e) => handleEnhanceToggle(e.target.checked)}
           className="rounded border-border accent-primary"
         />
-        <span className="text-sm text-muted-foreground">Enhance before scanning</span>
+        <span className="text-sm text-muted-foreground">
+          {t.toolSettings.ocr.enhanceBeforeScanning}
+        </span>
         <span
           title="Automatically deskews, enhances contrast, removes noise, and upscales the image before scanning for better accuracy."
           className="inline-flex items-center justify-center w-4 h-4 rounded-full border border-muted-foreground/40 text-muted-foreground/60 text-[10px] cursor-help"
@@ -263,7 +268,7 @@ export function OcrSettings() {
         >
           {langOpen ? <ChevronDown className="h-3 w-3" /> : <ChevronRight className="h-3 w-3" />}
           Language
-          <span className="ml-auto text-primary text-[10px] normal-case font-normal">
+          <span className="ms-auto text-primary text-[10px] normal-case font-normal">
             {langLabel}
           </span>
         </button>
@@ -290,7 +295,7 @@ export function OcrSettings() {
         <ProgressCard
           active={processing}
           phase={progressPhase === "idle" ? "uploading" : progressPhase}
-          label="Extracting text"
+          label={t.toolSettings.ocr.progressLabel}
           stage={progressStage}
           percent={progressPercent}
           elapsed={elapsed}
@@ -303,7 +308,9 @@ export function OcrSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Extract Text (${files.length} files)` : "Extract Text"}
+          {files.length > 1
+            ? format(t.toolSettings.ocr.submitBatch, { count: files.length })
+            : t.toolSettings.ocr.submit}
         </button>
       )}
 
@@ -311,7 +318,9 @@ export function OcrSettings() {
       {text !== null && (
         <div className="space-y-2">
           <div className="flex items-center justify-between">
-            <span className="text-xs font-medium text-muted-foreground">Extracted Text</span>
+            <span className="text-xs font-medium text-muted-foreground">
+              {t.toolSettings.ocr.extractedText}
+            </span>
             <div className="flex items-center gap-3">
               {text.length > 0 && (
                 <button
@@ -342,7 +351,9 @@ export function OcrSettings() {
                 rows={Math.min(16, Math.max(8, text.split("\n").length + 2))}
                 className="w-full px-2 py-1.5 rounded border border-border bg-muted text-xs text-foreground font-mono resize-y"
               />
-              <p className="text-[10px] text-muted-foreground">{text.length} characters</p>
+              <p className="text-[10px] text-muted-foreground">
+                {format(t.toolSettings.ocr.characters, { count: text.length })}
+              </p>
             </>
           ) : (
             <p className="text-xs text-muted-foreground italic py-4 text-center">

apps/web/src/components/tools/optimize-for-web-settings.tsx

@@ -330,7 +330,7 @@ export function OptimizeForWebSettings() {
           {preview.processedSize != null && (
             <div className="text-xs text-muted-foreground">
               Optimized: {formatSize(preview.processedSize)}
-              <span className="ml-1 font-medium uppercase text-[10px]">
+              <span className="ms-1 font-medium uppercase text-[10px]">
                 {FORMAT_LABELS[format]}
               </span>
             </div>

apps/web/src/components/tools/passport-photo-settings.tsx

@@ -20,6 +20,7 @@ import {
 import { useCallback, useEffect, useRef, useState } from "react";
 import { create } from "zustand";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
 import { formatHeaders } from "@/lib/api";
 import { useFileStore } from "@/stores/file-store";
@@ -324,7 +325,7 @@ function CountryOption({
       }`}
     >
       <span>{spec.flag}</span>
-      <span className="flex-1 text-left">{spec.name}</span>
+      <span className="flex-1 text-start">{spec.name}</span>
       <span className="text-muted-foreground/60 tabular-nums text-[10px]">
         {formatDimensions(doc)}
       </span>
@@ -336,6 +337,7 @@ function CountryOption({
 // ── Settings panel (left side) ─────────────────────────────────────
 
 export function PassportPhotoSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const { error } = useToolProcessor("passport-photo");
 
@@ -574,9 +576,9 @@ export function PassportPhotoSettings() {
           className="w-full flex items-center gap-2 px-3 py-2 rounded-lg border border-border bg-background text-sm text-foreground hover:border-primary/50 transition-colors"
         >
           <span>{selectedSpec.flag}</span>
-          <span className="flex-1 text-left truncate">
+          <span className="flex-1 text-start truncate">
             {selectedSpec.name}
-            <span className="text-muted-foreground ml-1.5 text-xs">
+            <span className="text-muted-foreground ms-1.5 text-xs">
               {formatDimensions(docSpec)}
             </span>
           </span>
@@ -605,7 +607,7 @@ export function PassportPhotoSettings() {
                   value={searchQuery}
                   onChange={(e) => setSearchQuery(e.target.value)}
                   placeholder="Search countries..."
-                  className="w-full pl-7 pr-2 py-1.5 rounded border border-border bg-background text-xs text-foreground placeholder:text-muted-foreground focus:outline-none focus:border-primary"
+                  className="w-full ps-7 pe-2 py-1.5 rounded border border-border bg-background text-xs text-foreground placeholder:text-muted-foreground focus:outline-none focus:border-primary"
                 />
               </div>
             </div>
@@ -626,7 +628,7 @@ export function PassportPhotoSettings() {
                   }`}
                 >
                   <span>{"\u2699\uFE0F"}</span>
-                  <span className="flex-1 text-left">Custom Dimensions</span>
+                  <span className="flex-1 text-start">Custom Dimensions</span>
                   {isCustom && <Check className="h-3 w-3 text-primary shrink-0" />}
                 </button>
               )}
@@ -894,6 +896,7 @@ export function PassportPhotoSettings() {
 // ── Preview panel (right side) ────────────────────────────────────
 
 export function PassportPhotoPreview() {
+  const { t } = useTranslation();
   const {
     analyzeResult,
     countryCode,
@@ -1154,7 +1157,7 @@ export function PassportPhotoPreview() {
             <RotateCcw className="h-3.5 w-3.5" />
           </button>
         )}
-        <span className="text-[10px] text-muted-foreground ml-auto">
+        <span className="text-[10px] text-muted-foreground ms-auto">
           {pxDims.w}x{pxDims.h}px
         </span>
       </div>

apps/web/src/components/tools/pdf-to-image-preview.tsx

@@ -82,7 +82,7 @@ export function PdfToImagePreview() {
             {store.results.length} page
             {store.results.length !== 1 ? "s" : ""} converted
             {totalSize > 0 && (
-              <span className="text-muted-foreground font-normal ml-1">
+              <span className="text-muted-foreground font-normal ms-1">
                 ({formatSize(totalSize)})
               </span>
             )}
@@ -187,7 +187,7 @@ export function PdfToImagePreview() {
                 key={thumb.page}
                 type="button"
                 onClick={() => store.togglePage(thumb.page)}
-                className={`relative rounded-lg border overflow-hidden text-left transition-all ${
+                className={`relative rounded-lg border overflow-hidden text-start transition-all ${
                   isSelected
                     ? "border-primary ring-1 ring-primary/30"
                     : "border-border opacity-50 hover:opacity-75"

apps/web/src/components/tools/pdf-to-image-settings.tsx

@@ -1,5 +1,7 @@
 import { Download, FileUp, Loader2, X } from "lucide-react";
 import { useCallback, useRef } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
+import { format } from "@/lib/format";
 import { usePdfToImageStore } from "@/stores/pdf-to-image-store";
 
 const FORMAT_OPTIONS = [
@@ -37,6 +39,7 @@ const COLOR_MODE_OPTIONS = [
 const LOSSY_FORMATS = ["jpg", "webp", "avif", "heic", "heif", "jxl"];
 
 export function PdfToImageSettings() {
+  const { t } = useTranslation();
   const store = usePdfToImageStore();
   const fileInputRef = useRef<HTMLInputElement>(null);
 
@@ -79,7 +82,7 @@ export function PdfToImageSettings() {
           className="border-2 border-dashed border-border rounded-lg p-6 text-center cursor-pointer hover:border-primary/50 transition-colors w-full"
         >
           <FileUp className="h-8 w-8 mx-auto mb-2 text-muted-foreground" />
-          <p className="text-sm text-muted-foreground">Drop a PDF here or click to select</p>
+          <p className="text-sm text-muted-foreground">{t.toolSettings["pdf-to-image"].dropPdf}</p>
           <input
             ref={fileInputRef}
             type="file"
@@ -115,7 +118,9 @@ export function PdfToImageSettings() {
 
       {/* Output Format - grid buttons */}
       <div>
-        <p className="text-xs text-muted-foreground mb-1.5">Output Format</p>
+        <p className="text-xs text-muted-foreground mb-1.5">
+          {t.toolSettings["pdf-to-image"].outputFormat}
+        </p>
         <div className="grid grid-cols-4 gap-1">
           {FORMAT_OPTIONS.map((opt) => (
             <button
@@ -138,7 +143,9 @@ export function PdfToImageSettings() {
       {isLossy && (
         <div>
           <div className="flex justify-between items-center">
-            <p className="text-xs text-muted-foreground">Quality</p>
+            <p className="text-xs text-muted-foreground">
+              {t.toolSettings["pdf-to-image"].quality}
+            </p>
             <span className="text-xs font-mono text-foreground">{store.quality}</span>
           </div>
           <input
@@ -154,7 +161,9 @@ export function PdfToImageSettings() {
 
       {/* DPI presets + custom */}
       <div>
-        <p className="text-xs text-muted-foreground mb-1.5">Resolution (DPI)</p>
+        <p className="text-xs text-muted-foreground mb-1.5">
+          {t.toolSettings["pdf-to-image"].resolutionDpi}
+        </p>
         <div className="grid grid-cols-5 gap-1">
           {DPI_PRESETS.map((opt) => (
             <button
@@ -204,7 +213,9 @@ export function PdfToImageSettings() {
 
       {/* Color Mode */}
       <div>
-        <p className="text-xs text-muted-foreground mb-1.5">Color Mode</p>
+        <p className="text-xs text-muted-foreground mb-1.5">
+          {t.toolSettings["pdf-to-image"].colorMode}
+        </p>
         <div className="grid grid-cols-3 gap-1">
           {COLOR_MODE_OPTIONS.map((opt) => (
             <button
@@ -226,7 +237,7 @@ export function PdfToImageSettings() {
       {/* Page range input */}
       <div>
         <label htmlFor="pdf-pages" className="text-xs text-muted-foreground">
-          Pages
+          {t.toolSettings["pdf-to-image"].pages}
         </label>
         <input
           id="pdf-pages"
@@ -256,7 +267,7 @@ export function PdfToImageSettings() {
       >
         {store.processing && <Loader2 className="h-4 w-4 animate-spin" />}
         {store.processing
-          ? "Converting..."
+          ? t.toolSettings["pdf-to-image"].converting
           : `Convert ${selectedCount} page${selectedCount !== 1 ? "s" : ""}`}
       </button>
 

apps/web/src/components/tools/pipeline-builder.tsx

@@ -16,7 +16,9 @@ import {
 import { CSS } from "@dnd-kit/utilities";
 import { TOOLS } from "@snapotter/shared";
 import { FileImage, GripVertical, X } from "lucide-react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { ICON_MAP } from "@/lib/icon-map";
+import { getToolName } from "@/lib/tool-i18n";
 import { cn } from "@/lib/utils";
 import type { PipelineStep } from "@/stores/pipeline-store";
 import { PipelineStepSettings } from "./pipeline-step-settings";
@@ -52,6 +54,7 @@ function SortableStep({
   onRemove,
   onUpdateSettings,
 }: SortableStepProps) {
+  const { t } = useTranslation();
   const { attributes, listeners, setNodeRef, transform, transition, isDragging } = useSortable({
     id: step.id,
   });
@@ -85,7 +88,7 @@ function SortableStep({
           role="button"
           tabIndex={0}
           onClick={onToggle}
-          className="flex items-center gap-2 p-3 w-full text-left cursor-pointer"
+          className="flex items-center gap-2 p-3 w-full text-start cursor-pointer"
         >
           {/* Drag handle */}
           {
@@ -108,11 +111,13 @@ function SortableStep({
 
           {/* Tool icon + name */}
           <Icon className="h-4 w-4 text-muted-foreground shrink-0" />
-          <span className="text-sm font-medium text-foreground">{tool.name}</span>
+          <span className="text-sm font-medium text-foreground">
+            {getToolName(t, tool.id, tool.name)}
+          </span>
 
           {/* Settings summary when collapsed */}
           {!isExpanded && summary && (
-            <span className="text-xs text-muted-foreground truncate ml-1">{summary}</span>
+            <span className="text-xs text-muted-foreground truncate ms-1">{summary}</span>
           )}
 
           <span className="flex-1" />

apps/web/src/components/tools/qr-generate-settings.tsx

@@ -13,6 +13,7 @@ import {
 import QRCodeStyling from "qr-code-styling";
 import { useCallback, useRef } from "react";
 import { CollapsibleSection } from "@/components/common/collapsible-section";
+import { useTranslation } from "@/contexts/i18n-context";
 import {
   type ContentType,
   type CornerDotType,
@@ -345,6 +346,7 @@ function PillButton({
 // ── Main settings component ──────────────────────────────────────────
 
 export function QrGenerateSettings() {
+  const { t } = useTranslation();
   const store = useQrStore();
   const logoInputRef = useRef<HTMLInputElement>(null);
 
@@ -515,7 +517,7 @@ export function QrGenerateSettings() {
           </label>
 
           {store.dotGradientEnabled && (
-            <div className="space-y-2 pl-2 border-l-2 border-primary/20 ml-1">
+            <div className="space-y-2 ps-2 border-s-2 border-primary/20 ms-1">
               <div className="flex gap-2">
                 <div className="flex-1">
                   <label htmlFor="qr-gradient-from" className="text-[10px] text-muted-foreground">
@@ -764,7 +766,7 @@ export function QrGenerateSettings() {
                   key={value}
                   type="button"
                   onClick={() => store.setDownloadFormat(value)}
-                  className={`text-left px-2 py-1.5 rounded transition-colors ${
+                  className={`text-start px-2 py-1.5 rounded transition-colors ${
                     store.downloadFormat === value
                       ? "bg-primary text-primary-foreground"
                       : "bg-muted text-muted-foreground hover:text-foreground"

apps/web/src/components/tools/red-eye-removal-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 const LOSSY_FORMATS = new Set(["jpeg", "webp", "avif", "jxl"]);
@@ -140,6 +142,7 @@ export function RedEyeRemovalControls({
 }
 
 export function RedEyeRemovalSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -196,7 +199,9 @@ export function RedEyeRemovalSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {hasMultiple ? `Fix Red Eye (${files.length} files)` : "Fix Red Eye"}
+          {hasMultiple
+            ? format(t.toolSettings["red-eye-removal"].submitBatch, { count: files.length })
+            : t.toolSettings["red-eye-removal"].submit}
         </button>
       )}
 

apps/web/src/components/tools/remove-bg-settings.tsx

@@ -9,8 +9,10 @@ import {
 } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
 import { formatHeaders } from "@/lib/api";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type SubjectType = "people" | "products" | "general";
@@ -84,6 +86,7 @@ export interface RemoveBgControlsProps {
 }
 
 export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgControlsProps) {
+  const { t } = useTranslation();
   const [subject, setSubject] = useState<SubjectType>("people");
   const [quality, setQuality] = useState<Quality>("balanced");
   const [isPassport, setIsPassport] = useState(true);
@@ -167,7 +170,7 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
   return (
     <div className="space-y-3">
       {/* Subject type */}
-      <SectionLabel>Subject</SectionLabel>
+      <SectionLabel>{t.toolSettings["remove-background"].subject}</SectionLabel>
       <div className="grid grid-cols-3 gap-1.5">
         {SUBJECT_OPTIONS.map((opt) => {
           const Icon = opt.icon;
@@ -202,12 +205,14 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
             onChange={(e) => setIsPassport(e.target.checked)}
             className="rounded border-border accent-primary"
           />
-          <span className="text-sm text-muted-foreground">Passport / ID photo</span>
+          <span className="text-sm text-muted-foreground">
+            {t.toolSettings["remove-background"].passportIdPhoto}
+          </span>
         </label>
       )}
 
       {/* Quality */}
-      <SectionLabel>Quality</SectionLabel>
+      <SectionLabel>{t.toolSettings["remove-background"].quality}</SectionLabel>
       <div className={`grid gap-1.5 ${qualityOptions.length > 3 ? "grid-cols-4" : "grid-cols-3"}`}>
         {qualityOptions.map((opt) => (
           <button
@@ -226,7 +231,7 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
       </div>
 
       {/* Background */}
-      <SectionLabel>Background</SectionLabel>
+      <SectionLabel>{t.toolSettings["remove-background"].background}</SectionLabel>
       <div className="space-y-2">
         {/* Type buttons */}
         <div className="flex gap-1.5 flex-wrap">
@@ -258,7 +263,7 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
 
         {/* Color options */}
         {bgType === "color" && (
-          <div className="space-y-2 pl-1">
+          <div className="space-y-2 ps-1">
             <div className="flex gap-1.5 flex-wrap">
               {COLOR_PRESETS.map((preset) => (
                 <button
@@ -293,7 +298,7 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
 
         {/* Gradient options */}
         {bgType === "gradient" && (
-          <div className="space-y-2 pl-1">
+          <div className="space-y-2 ps-1">
             <div className="flex gap-1.5 flex-wrap">
               {GRADIENT_PRESETS.map((preset) => (
                 <button
@@ -351,7 +356,7 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
 
         {/* Image upload */}
         {bgType === "image" && (
-          <div className="pl-1">
+          <div className="ps-1">
             {bgImageFile ? (
               <div className="flex items-center gap-2 text-xs">
                 <span className="text-foreground truncate flex-1">{bgImageFile.name}</span>
@@ -391,12 +396,12 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
         {effectsOpen ? <ChevronDown className="h-3 w-3" /> : <ChevronRight className="h-3 w-3" />}
         Effects
         {(blurEnabled || shadowEnabled) && (
-          <span className="ml-auto text-primary text-[10px] normal-case font-normal">active</span>
+          <span className="ms-auto text-primary text-[10px] normal-case font-normal">active</span>
         )}
       </button>
 
       {effectsOpen && (
-        <div className="space-y-3 pl-1">
+        <div className="space-y-3 ps-1">
           {/* Blur */}
           <div>
             <label className="flex items-center gap-2 cursor-pointer">
@@ -406,13 +411,15 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
                 onChange={(e) => setBlurEnabled(e.target.checked)}
                 className="rounded border-border accent-primary"
               />
-              <span className="text-xs text-muted-foreground">Blur Background</span>
+              <span className="text-xs text-muted-foreground">
+                {t.toolSettings["remove-background"].blurBackground}
+              </span>
             </label>
             {blurEnabled && (
-              <div className="mt-1.5 pl-5">
+              <div className="mt-1.5 ps-5">
                 <div className="flex justify-between items-center">
                   <span className="text-xs text-muted-foreground">Intensity</span>
-                  <span className="text-xs font-mono text-foreground tabular-nums w-8 text-right">
+                  <span className="text-xs font-mono text-foreground tabular-nums w-8 text-end">
                     {blurIntensity}
                   </span>
                 </div>
@@ -437,13 +444,15 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
                 onChange={(e) => setShadowEnabled(e.target.checked)}
                 className="rounded border-border accent-primary"
               />
-              <span className="text-xs text-muted-foreground">Add Shadow</span>
+              <span className="text-xs text-muted-foreground">
+                {t.toolSettings["remove-background"].addShadow}
+              </span>
             </label>
             {shadowEnabled && (
-              <div className="mt-1.5 pl-5">
+              <div className="mt-1.5 ps-5">
                 <div className="flex justify-between items-center">
                   <span className="text-xs text-muted-foreground">Opacity</span>
-                  <span className="text-xs font-mono text-foreground tabular-nums w-8 text-right">
+                  <span className="text-xs font-mono text-foreground tabular-nums w-8 text-end">
                     {shadowOpacity}
                   </span>
                 </div>
@@ -526,6 +535,7 @@ interface RemoveBgSettingsProps {
 }
 
 export function RemoveBgSettings({ onBgPreview }: RemoveBgSettingsProps = {}) {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -796,7 +806,7 @@ export function RemoveBgSettings({ onBgPreview }: RemoveBgSettingsProps = {}) {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Removing background"
+          label={t.toolSettings["remove-background"].progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -809,7 +819,9 @@ export function RemoveBgSettings({ onBgPreview }: RemoveBgSettingsProps = {}) {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Remove Background (${files.length} files)` : "Remove Background"}
+          {files.length > 1
+            ? format(t.toolSettings["remove-background"].submitBatch, { count: files.length })
+            : t.toolSettings["remove-background"].submit}
         </button>
       ) : null}
 
@@ -825,7 +837,7 @@ export function RemoveBgSettings({ onBgPreview }: RemoveBgSettingsProps = {}) {
               className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
             >
               <Download className="h-4 w-4" />
-              {applyingEffects ? "Rendering..." : "Download"}
+              {applyingEffects ? t.toolSettings["remove-background"].rendering : "Download"}
             </button>
           ) : (
             <a

apps/web/src/components/tools/resize-settings.tsx

@@ -2,17 +2,15 @@ import { SOCIAL_MEDIA_PRESETS } from "@snapotter/shared";
 import { Download, Info, Link, Unlink } from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type ResizeTab = "presets" | "custom" | "scale" | "content-aware";
 type FitMode = "cover" | "contain" | "fill";
 
-const FIT_LABELS: Record<FitMode, string> = {
-  cover: "Crop to fit",
-  contain: "Fit inside",
-  fill: "Stretch",
-};
+const FIT_MODES: FitMode[] = ["cover", "contain", "fill"];
 
 // Group presets by platform
 const platforms = [...new Set(SOCIAL_MEDIA_PRESETS.map((p) => p.platform))];
@@ -34,6 +32,7 @@ export interface ResizeControlsProps {
 }
 
 export function ResizeControls({ settings: initialSettings, onChange }: ResizeControlsProps) {
+  const { t } = useTranslation();
   const [tab, setTab] = useState<ResizeTab>("custom");
   const [selectedPreset, setSelectedPreset] = useState<string | null>(null);
   const [width, setWidth] = useState<string>("");
@@ -127,7 +126,7 @@ export function ResizeControls({ settings: initialSettings, onChange }: ResizeCo
     <div className="flex items-end gap-2">
       <div className="flex-1">
         <label htmlFor="resize-width" className="text-xs text-muted-foreground">
-          Width (px)
+          {t.toolSettings.resize.widthPx}
         </label>
         <input
           id="resize-width"
@@ -149,7 +148,7 @@ export function ResizeControls({ settings: initialSettings, onChange }: ResizeCo
       </button>
       <div className="flex-1">
         <label htmlFor="resize-height" className="text-xs text-muted-foreground">
-          Height (px)
+          {t.toolSettings.resize.heightPx}
         </label>
         <input
           id="resize-height"
@@ -172,8 +171,8 @@ export function ResizeControls({ settings: initialSettings, onChange }: ResizeCo
         onChange={(e) => setWithoutEnlargement(e.target.checked)}
         className="rounded"
       />
-      <span>Limit to original size</span>
-      <HintIcon text="If your image is already smaller than the target, keep it as-is instead of scaling it up" />
+      <span>{t.toolSettings.resize.limitToOriginalSize}</span>
+      <HintIcon text={t.toolSettings.resize.limitToOriginalSizeHint} />
     </label>
   );
 
@@ -183,27 +182,27 @@ export function ResizeControls({ settings: initialSettings, onChange }: ResizeCo
       <div>
         <div className="flex gap-1">
           <button type="button" onClick={() => setTab("custom")} className={tabClass("custom")}>
-            Custom Size
+            {t.toolSettings.resize.customSize}
           </button>
           <button type="button" onClick={() => setTab("scale")} className={tabClass("scale")}>
-            Scale
+            {t.toolSettings.resize.scale}
           </button>
           <button type="button" onClick={() => setTab("presets")} className={tabClass("presets")}>
-            Presets
+            {t.toolSettings.resize.presets}
           </button>
           <button
             type="button"
             onClick={() => setTab("content-aware")}
             className={tabClass("content-aware")}
           >
-            Content-Aware
+            {t.toolSettings.resize.contentAware}
           </button>
         </div>
       </div>
 
       {/* Presets tab */}
       {tab === "presets" && (
-        <div className="space-y-3 max-h-[50vh] overflow-y-auto pr-1">
+        <div className="space-y-3 max-h-[50vh] overflow-y-auto pe-1">
           {platforms.map((platform) => (
             <div key={platform}>
               <p className="text-xs font-medium text-muted-foreground mb-1.5">{platform}</p>
@@ -244,16 +243,20 @@ export function ResizeControls({ settings: initialSettings, onChange }: ResizeCo
 
           {/* Fit mode */}
           <div>
-            <p className="text-xs text-muted-foreground">Fit Mode</p>
+            <p className="text-xs text-muted-foreground">{t.toolSettings.resize.fitMode}</p>
             <div className="flex gap-1 mt-1">
-              {(Object.keys(FIT_LABELS) as FitMode[]).map((f) => (
+              {FIT_MODES.map((f) => (
                 <button
                   key={f}
                   type="button"
                   onClick={() => setFit(f)}
                   className={`flex-1 text-xs py-1.5 rounded ${fit === f ? "bg-primary text-primary-foreground" : "bg-muted text-muted-foreground"}`}
                 >
-                  {FIT_LABELS[f]}
+                  {f === "cover"
+                    ? t.toolSettings.resize.cropToFit
+                    : f === "contain"
+                      ? t.toolSettings.resize.fitInside
+                      : t.toolSettings.resize.stretch}
                 </button>
               ))}
             </div>
@@ -311,7 +314,7 @@ export function ResizeControls({ settings: initialSettings, onChange }: ResizeCo
               onChange={(e) => setSquareMode(e.target.checked)}
               className="rounded"
             />
-            Resize to square
+            {t.toolSettings.resize.resizeToSquare}
           </label>
 
           {/* Face protection */}
@@ -322,7 +325,7 @@ export function ResizeControls({ settings: initialSettings, onChange }: ResizeCo
               onChange={(e) => setProtectFaces(e.target.checked)}
               className="rounded"
             />
-            Protect faces
+            {t.toolSettings.resize.protectFaces}
           </label>
 
           {/* Blur radius */}
@@ -369,6 +372,7 @@ export function ResizeControls({ settings: initialSettings, onChange }: ResizeCo
 }
 
 export function ResizeSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const standardResize = useToolProcessor("resize");
   const contentAwareResize = useToolProcessor("content-aware-resize");
@@ -420,7 +424,7 @@ export function ResizeSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Resizing"
+          label={t.toolSettings.resize.progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -432,7 +436,9 @@ export function ResizeSettings() {
           disabled={!canProcess}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Resize (${files.length} files)` : "Resize"}
+          {files.length > 1
+            ? format(t.toolSettings.resize.submitBatch, { count: files.length })
+            : t.toolSettings.resize.submit}
         </button>
       )}
 
@@ -445,7 +451,7 @@ export function ResizeSettings() {
           className="w-full py-2.5 rounded-lg border border-primary text-primary font-medium flex items-center justify-center gap-2 hover:bg-primary/5"
         >
           <Download className="h-4 w-4" />
-          Download
+          {t.common.download}
         </a>
       )}
     </form>

apps/web/src/components/tools/restore-photo-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 export interface RestorePhotoControlsProps {
@@ -13,6 +15,7 @@ export function RestorePhotoControls({
   settings: initialSettings,
   onChange,
 }: RestorePhotoControlsProps) {
+  const { t } = useTranslation();
   const [scratchRemoval, setScratchRemoval] = useState(true);
   const [faceEnhancement, setFaceEnhancement] = useState(true);
   const [fidelity, setFidelity] = useState(70);
@@ -103,7 +106,7 @@ export function RestorePhotoControls({
 
         {/* Fidelity slider (only when face enhancement is on) */}
         {faceEnhancement && (
-          <div className="pl-2 border-l-2 border-primary/20">
+          <div className="ps-2 border-s-2 border-primary/20">
             <div className="flex justify-between items-center">
               <p className="text-xs text-muted-foreground">Face Fidelity</p>
               <span className="text-xs font-mono tabular-nums">{fidelity}%</span>
@@ -142,7 +145,7 @@ export function RestorePhotoControls({
 
         {/* Denoise strength slider */}
         {denoise && (
-          <div className="pl-2 border-l-2 border-primary/20">
+          <div className="ps-2 border-s-2 border-primary/20">
             <div className="flex justify-between items-center">
               <p className="text-xs text-muted-foreground">Denoise Strength</p>
               <span className="text-xs font-mono tabular-nums">{denoiseStrength}</span>
@@ -183,7 +186,7 @@ export function RestorePhotoControls({
 
         {/* Colorize strength slider */}
         {colorize && (
-          <div className="pl-2 border-l-2 border-primary/20">
+          <div className="ps-2 border-s-2 border-primary/20">
             <div className="flex justify-between items-center">
               <p className="text-xs text-muted-foreground">Colorize Strength</p>
               <span className="text-xs font-mono tabular-nums">{colorizeStrength}%</span>
@@ -209,6 +212,7 @@ export function RestorePhotoControls({
 }
 
 export function RestorePhotoSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -265,7 +269,9 @@ export function RestorePhotoSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {hasMultiple ? `Restore Photos (${files.length})` : "Restore Photo"}
+          {hasMultiple
+            ? format(t.toolSettings["restore-photo"].submitBatch, { count: files.length })
+            : t.toolSettings["restore-photo"].submit}
         </button>
       )}
 

apps/web/src/components/tools/rotate-settings.tsx

@@ -162,7 +162,7 @@ export function RotateControls({
                   commitAngleInput();
                 }
               }}
-              className="w-16 text-center text-sm font-mono font-medium tabular-nums py-1.5 rounded-md bg-background border border-border focus:outline-none focus:ring-2 focus:ring-primary/50 pr-4"
+              className="w-16 text-center text-sm font-mono font-medium tabular-nums py-1.5 rounded-md bg-background border border-border focus:outline-none focus:ring-2 focus:ring-primary/50 pe-4"
             />
             <span className="absolute right-2 text-sm font-mono text-muted-foreground pointer-events-none">
               °

apps/web/src/components/tools/sharpening-settings.tsx

@@ -2,7 +2,9 @@ import { ChevronDown, ChevronRight, Download } from "lucide-react";
 import type React from "react";
 import { useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type Method = "adaptive" | "unsharp-mask" | "high-pass";
@@ -29,6 +31,7 @@ const PRESETS: Preset[] = [
 ];
 
 export function SharpeningSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -103,7 +106,7 @@ export function SharpeningSettings() {
   return (
     <form onSubmit={handleSubmit} className="space-y-3">
       {/* Method selector */}
-      <SectionLabel>Method</SectionLabel>
+      <SectionLabel>{t.toolSettings.sharpening.method}</SectionLabel>
       <div className="grid grid-cols-3 gap-1">
         {(["adaptive", "unsharp-mask", "high-pass"] as const).map((m) => (
           <button
@@ -127,7 +130,7 @@ export function SharpeningSettings() {
       {/* Presets (adaptive only) */}
       {method === "adaptive" && (
         <>
-          <SectionLabel>Presets</SectionLabel>
+          <SectionLabel>{t.toolSettings.sharpening.presets}</SectionLabel>
           <div className="grid grid-cols-4 gap-1">
             {PRESETS.map((p) => (
               <button
@@ -199,7 +202,7 @@ export function SharpeningSettings() {
       </div>
 
       {/* Noise reduction */}
-      <SectionLabel>Noise Reduction</SectionLabel>
+      <SectionLabel>{t.toolSettings.sharpening.noiseReduction}</SectionLabel>
       <div className="grid grid-cols-4 gap-1">
         {(["off", "light", "medium", "strong"] as const).map((d) => (
           <button
@@ -228,7 +231,7 @@ export function SharpeningSettings() {
       </button>
 
       {advancedOpen && (
-        <div className="space-y-2 pl-1">
+        <div className="space-y-2 ps-1">
           {method === "adaptive" && (
             <>
               <SliderControl
@@ -359,7 +362,7 @@ export function SharpeningSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Sharpening"
+          label={t.toolSettings.sharpening.progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -371,7 +374,9 @@ export function SharpeningSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Sharpen (${files.length} files)` : "Sharpen"}
+          {files.length > 1
+            ? format(t.toolSettings.sharpening.submitBatch, { count: files.length })
+            : t.toolSettings.sharpening.submit}
         </button>
       )}
 
@@ -424,9 +429,9 @@ function SliderControl({
       <div className="flex justify-between items-center">
         <label htmlFor={id} className={`text-xs ${color || "text-muted-foreground"}`}>
           {label}
-          {hint && <span className="text-[10px] text-muted-foreground/60 ml-1">({hint})</span>}
+          {hint && <span className="text-[10px] text-muted-foreground/60 ms-1">({hint})</span>}
         </label>
-        <span className="text-xs font-mono text-foreground tabular-nums w-10 text-right">
+        <span className="text-xs font-mono text-foreground tabular-nums w-10 text-end">
           {displayValue}
         </span>
       </div>

apps/web/src/components/tools/smart-crop-settings.tsx

@@ -2,7 +2,9 @@ import { SMART_CROP_FACE_PRESETS, SOCIAL_MEDIA_PRESETS } from "@snapotter/shared
 import { ArrowLeftRight, Info } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type CropMode = "subject" | "face" | "trim";
@@ -36,6 +38,7 @@ export interface SmartCropControlsProps {
 }
 
 export function SmartCropControls({ settings: initialSettings, onChange }: SmartCropControlsProps) {
+  const { t } = useTranslation();
   const [mode, setMode] = useState<CropMode>("subject");
   const [subjectTab, setSubjectTab] = useState<SubjectTab>("custom");
   const [selectedPreset, setSelectedPreset] = useState<string | null>(null);
@@ -261,13 +264,13 @@ export function SmartCropControls({ settings: initialSettings, onChange }: Smart
           onClick={() => setMode("subject")}
           className={modeTabClass("subject")}
         >
-          Subject Focus
+          {t.toolSettings["smart-crop"].subjectFocus}
         </button>
         <button type="button" onClick={() => setMode("face")} className={modeTabClass("face")}>
-          Face Focus
+          {t.toolSettings["smart-crop"].faceFocus}
         </button>
         <button type="button" onClick={() => setMode("trim")} className={modeTabClass("trim")}>
-          Auto Trim
+          {t.toolSettings["smart-crop"].autoTrim}
         </button>
       </div>
 
@@ -293,7 +296,7 @@ export function SmartCropControls({ settings: initialSettings, onChange }: Smart
           </div>
 
           {subjectTab === "presets" ? (
-            <div className="space-y-3 max-h-[50vh] overflow-y-auto pr-1">
+            <div className="space-y-3 max-h-[50vh] overflow-y-auto pe-1">
               {platforms.map((platform) => (
                 <div key={platform}>
                   <p className="text-xs font-medium text-muted-foreground mb-1.5">{platform}</p>
@@ -333,7 +336,9 @@ export function SmartCropControls({ settings: initialSettings, onChange }: Smart
           {/* Strategy toggle */}
           <div>
             <div className="flex items-center gap-1.5 mb-1">
-              <span className="text-xs text-muted-foreground">Detection Strategy</span>
+              <span className="text-xs text-muted-foreground">
+                {t.toolSettings["smart-crop"].detectionStrategy}
+              </span>
               <HintIcon text="Attention finds the most visually salient region. Entropy finds the area with most detail and information." />
             </div>
             <div className="flex gap-1">
@@ -546,6 +551,7 @@ export function SmartCropControls({ settings: initialSettings, onChange }: Smart
 }
 
 export function SmartCropSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const { processFiles, processAllFiles, processing, error, progress } =
     useToolProcessor("smart-crop");

apps/web/src/components/tools/split-settings.tsx

@@ -1,6 +1,7 @@
 import { Download, Loader2, PackageOpen } from "lucide-react";
 import { useCallback, useEffect, useState } from "react";
 import { CollapsibleSection } from "@/components/common/collapsible-section";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
 import { useFileStore } from "@/stores/file-store";
 import type { SplitMode } from "@/stores/split-store";
@@ -35,6 +36,7 @@ const OUTPUT_FORMATS = [
 const LOSSY_FORMATS = new Set(["jpg", "webp", "avif", "jxl"]);
 
 export function SplitSettings() {
+  const { t } = useTranslation();
   const { files, processing: fileStoreProcessing } = useFileStore();
   const {
     mode,

apps/web/src/components/tools/stitch-settings.tsx

@@ -1,5 +1,6 @@
 import { Download, Loader2 } from "lucide-react";
 import { useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
 import { useFileStore } from "@/stores/file-store";
 
@@ -9,6 +10,7 @@ type Alignment = "start" | "center" | "end";
 type OutputFormat = "png" | "jpeg" | "webp" | "avif" | "jxl";
 
 export function StitchSettings() {
+  const { t } = useTranslation();
   const { files, processing, error, setProcessing, setError, setProcessedUrl, setSizes, setJobId } =
     useFileStore();
 

apps/web/src/components/tools/strip-metadata-settings.tsx

@@ -143,7 +143,7 @@ export function StripMetadataControls({
           />
           Strip EXIF (camera info, date, exposure)
           {hasExif && !stripAll && (
-            <span className="ml-auto text-[10px] text-muted-foreground">
+            <span className="ms-auto text-[10px] text-muted-foreground">
               {Object.keys(metadata?.exif ?? {}).filter((k) => !SKIP_KEYS.has(k)).length} fields
             </span>
           )}
@@ -161,7 +161,7 @@ export function StripMetadataControls({
           />
           Strip GPS (location data)
           {hasGps && !stripAll && (
-            <span className="ml-auto text-[10px] text-amber-500">location found</span>
+            <span className="ms-auto text-[10px] text-amber-500">location found</span>
           )}
         </label>
 

apps/web/src/components/tools/text-overlay-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 export interface TextOverlayControlsProps {
@@ -155,6 +157,7 @@ export function TextOverlayControls({
 }
 
 export function TextOverlaySettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,

apps/web/src/components/tools/tool-palette.tsx

@@ -2,8 +2,10 @@ import { CATEGORIES, TOOLS } from "@snapotter/shared";
 import { FileImage, Plus } from "lucide-react";
 import { useEffect, useMemo, useState } from "react";
 import { SearchBar } from "@/components/common/search-bar";
+import { useTranslation } from "@/contexts/i18n-context";
 import { apiGet } from "@/lib/api";
 import { ICON_MAP } from "@/lib/icon-map";
+import { getCategoryName, getToolDescription, getToolName } from "@/lib/tool-i18n";
 import { cn } from "@/lib/utils";
 
 const EXCLUDED_TOOLS = new Set(["pipeline", "compare", "find-duplicates", "collage", "compose"]);
@@ -14,6 +16,7 @@ interface ToolPaletteProps {
 }
 
 export function ToolPalette({ onAddStep, className }: ToolPaletteProps) {
+  const { t } = useTranslation();
   const [search, setSearch] = useState("");
   const [disabledTools, setDisabledTools] = useState<string[]>([]);
   const [experimentalEnabled, setExperimentalEnabled] = useState(false);
@@ -87,7 +90,7 @@ export function ToolPalette({ onAddStep, className }: ToolPaletteProps) {
                   <div className="flex items-center gap-1.5 mb-1.5 px-1">
                     <CatIcon className="h-3.5 w-3.5 text-muted-foreground" />
                     <span className="text-xs font-semibold uppercase text-muted-foreground tracking-wider">
-                      {cat.name}
+                      {getCategoryName(t, cat.id, cat.name)}
                     </span>
                   </div>
                   <div className="space-y-0.5">
@@ -111,21 +114,24 @@ interface ToolItemProps {
 }
 
 function ToolItem({ tool, onAdd }: ToolItemProps) {
+  const { t } = useTranslation();
   const Icon = (ICON_MAP[tool.icon] as React.ComponentType<{ className?: string }>) ?? FileImage;
 
   return (
     <button
       type="button"
       onClick={() => onAdd(tool.id)}
-      className="flex items-center gap-2.5 w-full px-2.5 py-2 rounded-lg hover:bg-muted text-left transition-colors group"
+      className="flex items-center gap-2.5 w-full px-2.5 py-2 rounded-lg hover:bg-muted text-start transition-colors group"
     >
       <div className="p-1.5 rounded-md bg-muted group-hover:bg-primary/10 transition-colors shrink-0">
         <Icon className="h-3.5 w-3.5 text-muted-foreground group-hover:text-primary transition-colors" />
       </div>
       <div className="flex-1 min-w-0">
-        <div className="text-sm font-medium text-foreground leading-tight">{tool.name}</div>
+        <div className="text-sm font-medium text-foreground leading-tight">
+          {getToolName(t, tool.id, tool.name)}
+        </div>
         <div className="text-[11px] text-muted-foreground truncate leading-tight">
-          {tool.description}
+          {getToolDescription(t, tool.id, tool.description)}
         </div>
       </div>
       <Plus className="h-3.5 w-3.5 text-muted-foreground opacity-0 group-hover:opacity-100 transition-opacity shrink-0" />

apps/web/src/components/tools/transparency-fixer-settings.tsx

@@ -1,7 +1,9 @@
 import { ChevronDown, ChevronRight, Droplets } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type OutputFormat = "png" | "webp";
@@ -17,6 +19,7 @@ export function TransparencyFixerControls({
   settings: _settings,
   onChange,
 }: TransparencyFixerControlsProps) {
+  const { t } = useTranslation();
   const [defringe, setDefringe] = useState(30);
   const [outputFormat, setOutputFormat] = useState<OutputFormat>("png");
   const [removeWatermark, setRemoveWatermark] = useState(false);
@@ -76,12 +79,12 @@ export function TransparencyFixerControls({
       </button>
 
       {advancedOpen && (
-        <div className="space-y-3 pl-1">
+        <div className="space-y-3 ps-1">
           {/* Defringe slider */}
           <div>
             <div className="flex justify-between items-center">
               <span className="text-xs text-muted-foreground">Defringe</span>
-              <span className="text-xs font-mono text-foreground tabular-nums w-8 text-right">
+              <span className="text-xs font-mono text-foreground tabular-nums w-8 text-end">
                 {defringe}
               </span>
             </div>
@@ -118,6 +121,7 @@ export function TransparencyFixerControls({
 // ── Standalone tool page wrapper ──
 
 export function TransparencyFixerSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const { processFiles, processAllFiles, processing, error, progress } =
     useToolProcessor("transparency-fixer");
@@ -160,7 +164,9 @@ export function TransparencyFixerSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed"
         >
-          {hasMultiple ? `Fix Transparency (${files.length} files)` : "Fix Transparency"}
+          {hasMultiple
+            ? format(t.toolSettings["transparency-fixer"].submitBatch, { count: files.length })
+            : t.toolSettings["transparency-fixer"].submit}
         </button>
       )}
     </div>

apps/web/src/components/tools/upscale-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 const QUICK_SCALES = [2, 3, 4, 6, 8];
@@ -29,6 +31,7 @@ export interface UpscaleControlsProps {
 }
 
 export function UpscaleControls({ settings: initialSettings, onChange }: UpscaleControlsProps) {
+  const { t } = useTranslation();
   const [scale, setScale] = useState(2);
   const [model, setModel] = useState<"auto" | "realesrgan" | "lanczos">("auto");
   const [faceEnhance, setFaceEnhance] = useState(false);
@@ -70,7 +73,9 @@ export function UpscaleControls({ settings: initialSettings, onChange }: Upscale
       {/* Scale factor */}
       <div>
         <div className="flex justify-between items-center">
-          <p className="text-sm font-medium text-muted-foreground">Scale Factor</p>
+          <p className="text-sm font-medium text-muted-foreground">
+            {t.toolSettings.upscale.scaleFactor}
+          </p>
           <span className="text-sm font-mono font-medium">{scale}x</span>
         </div>
         <div className="flex gap-1 mt-1.5">
@@ -130,14 +135,16 @@ export function UpscaleControls({ settings: initialSettings, onChange }: Upscale
             onChange={(e) => setFaceEnhance(e.target.checked)}
             className="rounded border-border"
           />
-          <span className="text-sm text-foreground">Enhance faces</span>
+          <span className="text-sm text-foreground">{t.toolSettings.upscale.enhanceFaces}</span>
         </label>
       )}
 
       {/* Noise Reduction */}
       <div>
         <div className="flex justify-between items-center">
-          <p className="text-sm font-medium text-muted-foreground">Noise Reduction</p>
+          <p className="text-sm font-medium text-muted-foreground">
+            {t.toolSettings.upscale.noiseReduction}
+          </p>
           <span className="text-sm font-mono font-medium">
             {denoise === 0 ? "Off" : denoise.toFixed(1)}
           </span>
@@ -198,6 +205,7 @@ export function UpscaleControls({ settings: initialSettings, onChange }: Upscale
 }
 
 export function UpscaleSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -242,7 +250,7 @@ export function UpscaleSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label={hasMultiple ? `Upscaling ${files.length} images` : "Upscaling image"}
+          label={t.toolSettings.upscale.progressLabel}
           percent={progress.percent}
           elapsed={progress.elapsed}
         />
@@ -255,8 +263,11 @@ export function UpscaleSettings() {
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
           {hasMultiple
-            ? `Upscale ${(settings.scale as number) ?? 2}x (${files.length} files)`
-            : `Upscale ${(settings.scale as number) ?? 2}x`}
+            ? format(t.toolSettings.upscale.submitBatch, {
+                scale: (settings.scale as number) ?? 2,
+                count: files.length,
+              })
+            : format(t.toolSettings.upscale.submit, { scale: (settings.scale as number) ?? 2 })}
         </button>
       )}
 

apps/web/src/components/tools/vectorize-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type ColorMode = "bw" | "color";
@@ -72,6 +74,7 @@ function speckleToDetail(speckle: number): Detail {
 }
 
 export function VectorizeSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -353,7 +356,7 @@ export function VectorizeSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Vectorizing"
+          label={t.toolSettings.vectorize.progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}
@@ -366,7 +369,9 @@ export function VectorizeSettings() {
           disabled={!hasFile || processing}
           className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
         >
-          {files.length > 1 ? `Vectorize (${files.length} files)` : "Vectorize"}
+          {files.length > 1
+            ? format(t.toolSettings.vectorize.submitBatch, { count: files.length })
+            : t.toolSettings.vectorize.submit}
         </button>
       )}
 

apps/web/src/components/tools/watermark-image-settings.tsx

@@ -1,10 +1,13 @@
 import { Download, Loader2, Upload } from "lucide-react";
 import { useRef, useState } from "react";
+import { useTranslation } from "@/contexts/i18n-context";
 import { formatHeaders } from "@/lib/api";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type Position = "center" | "top-left" | "top-right" | "bottom-left" | "bottom-right";
 export function WatermarkImageSettings() {
+  const { t } = useTranslation();
   const { files, processing, error, setProcessing, setError, setProcessedUrl, setSizes, setJobId } =
     useFileStore();
   const [position, setPosition] = useState<Position>("bottom-right");
@@ -198,8 +201,8 @@ export function WatermarkImageSettings() {
         {processing
           ? "Processing..."
           : files.length > 1
-            ? `Apply Watermark (${files.length} files)`
-            : "Apply Watermark"}
+            ? format(t.toolSettings["watermark-image"].submitBatch, { count: files.length })
+            : t.toolSettings["watermark-image"].submit}
       </button>
 
       {downloadUrl && (

apps/web/src/components/tools/watermark-text-settings.tsx

@@ -1,7 +1,9 @@
 import { Download } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 import { ProgressCard } from "@/components/common/progress-card";
+import { useTranslation } from "@/contexts/i18n-context";
 import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { format } from "@/lib/format";
 import { useFileStore } from "@/stores/file-store";
 
 type Position = "center" | "top-left" | "top-right" | "bottom-left" | "bottom-right" | "tiled";
@@ -149,6 +151,7 @@ export function WatermarkTextControls({
 }
 
 export function WatermarkTextSettings() {
+  const { t } = useTranslation();
   const { files } = useFileStore();
   const {
     processFiles,
@@ -190,7 +193,7 @@ export function WatermarkTextSettings() {
         <ProgressCard
           active={processing}
           phase={progress.phase === "idle" ? "uploading" : progress.phase}
-          label="Adding watermark"
+          label={t.toolSettings["watermark-text"].progressLabel}
           stage={progress.stage}
           percent={progress.percent}
           elapsed={progress.elapsed}

apps/web/src/contexts/i18n-context.tsx

@@ -0,0 +1,152 @@
+import type { SupportedLocale, TranslationKeys } from "@snapotter/shared";
+import { en, SUPPORTED_LOCALES } from "@snapotter/shared";
+import { createContext, useCallback, useContext, useEffect, useState } from "react";
+
+type LocaleModule = Record<string, TranslationKeys>;
+
+const localeLoaders: Record<string, () => Promise<LocaleModule>> = {
+  "zh-CN": () => import("@snapotter/shared/i18n/zh-CN.js") as Promise<LocaleModule>,
+  "zh-TW": () => import("@snapotter/shared/i18n/zh-TW.js") as Promise<LocaleModule>,
+  ja: () => import("@snapotter/shared/i18n/ja.js") as Promise<LocaleModule>,
+  ko: () => import("@snapotter/shared/i18n/ko.js") as Promise<LocaleModule>,
+  es: () => import("@snapotter/shared/i18n/es.js") as Promise<LocaleModule>,
+  fr: () => import("@snapotter/shared/i18n/fr.js") as Promise<LocaleModule>,
+  it: () => import("@snapotter/shared/i18n/it.js") as Promise<LocaleModule>,
+  "pt-BR": () => import("@snapotter/shared/i18n/pt-BR.js") as Promise<LocaleModule>,
+  de: () => import("@snapotter/shared/i18n/de.js") as Promise<LocaleModule>,
+  nl: () => import("@snapotter/shared/i18n/nl.js") as Promise<LocaleModule>,
+  sv: () => import("@snapotter/shared/i18n/sv.js") as Promise<LocaleModule>,
+  ru: () => import("@snapotter/shared/i18n/ru.js") as Promise<LocaleModule>,
+  pl: () => import("@snapotter/shared/i18n/pl.js") as Promise<LocaleModule>,
+  uk: () => import("@snapotter/shared/i18n/uk.js") as Promise<LocaleModule>,
+  ar: () => import("@snapotter/shared/i18n/ar.js") as Promise<LocaleModule>,
+  tr: () => import("@snapotter/shared/i18n/tr.js") as Promise<LocaleModule>,
+  hi: () => import("@snapotter/shared/i18n/hi.js") as Promise<LocaleModule>,
+  vi: () => import("@snapotter/shared/i18n/vi.js") as Promise<LocaleModule>,
+  id: () => import("@snapotter/shared/i18n/id.js") as Promise<LocaleModule>,
+  th: () => import("@snapotter/shared/i18n/th.js") as Promise<LocaleModule>,
+};
+
+async function loadLocale(code: string): Promise<TranslationKeys> {
+  if (code === "en") return en;
+  const loader = localeLoaders[code];
+  if (!loader) return en;
+  try {
+    const mod = await loader();
+    const camelCode = code.replace(/-([a-zA-Z])/g, (_, c: string) => c.toUpperCase());
+    return (mod[camelCode] ?? mod[code] ?? en) as TranslationKeys;
+  } catch {
+    return en;
+  }
+}
+
+type I18nContextValue = {
+  t: TranslationKeys;
+  locale: string;
+  dir: "ltr" | "rtl";
+  setLocale: (code: string) => void;
+  supportedLocales: SupportedLocale[];
+};
+
+const I18nContext = createContext<I18nContextValue>({
+  t: en,
+  locale: "en",
+  dir: "ltr",
+  setLocale: () => {},
+  supportedLocales: SUPPORTED_LOCALES,
+});
+
+const LOCALE_STORAGE_KEY = "snapotter-locale";
+
+function detectLocale(): string {
+  const stored = localStorage.getItem(LOCALE_STORAGE_KEY);
+  if (stored) return stored;
+
+  const codes = SUPPORTED_LOCALES.map((l) => l.code);
+  for (const browserLang of navigator.languages) {
+    if (codes.includes(browserLang)) return browserLang;
+    const prefix = browserLang.split("-")[0];
+    const match = codes.find((c) => c === prefix || c.startsWith(`${prefix}-`));
+    if (match) return match;
+  }
+
+  return "en";
+}
+
+async function fetchInstanceDefault(): Promise<string> {
+  try {
+    const res = await fetch("/api/v1/config/locale");
+    if (res.ok) {
+      const data = await res.json();
+      if (data.defaultLocale && data.defaultLocale !== "en") {
+        return data.defaultLocale;
+      }
+    }
+  } catch {
+    // Server unreachable
+  }
+  return "en";
+}
+
+function getDir(code: string): "ltr" | "rtl" {
+  return SUPPORTED_LOCALES.find((l) => l.code === code)?.dir ?? "ltr";
+}
+
+export function I18nProvider({ children }: { children: React.ReactNode }) {
+  const [locale, setLocaleState] = useState(() => detectLocale());
+  const [translations, setTranslations] = useState<TranslationKeys>(en);
+  const dir = getDir(locale);
+
+  useEffect(() => {
+    const hasExplicitChoice = localStorage.getItem(LOCALE_STORAGE_KEY);
+    if (hasExplicitChoice) return;
+
+    if (detectLocale() !== "en") return;
+
+    let cancelled = false;
+    fetchInstanceDefault().then((instanceLocale) => {
+      if (!cancelled && instanceLocale !== "en") {
+        setLocaleState(instanceLocale);
+      }
+    });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
+  useEffect(() => {
+    let cancelled = false;
+    loadLocale(locale).then((t) => {
+      if (!cancelled) setTranslations(t);
+    });
+    return () => {
+      cancelled = true;
+    };
+  }, [locale]);
+
+  useEffect(() => {
+    document.documentElement.lang = locale;
+    document.documentElement.dir = dir;
+  }, [locale, dir]);
+
+  const setLocale = useCallback((code: string) => {
+    localStorage.setItem(LOCALE_STORAGE_KEY, code);
+    setLocaleState(code);
+  }, []);
+
+  return (
+    <I18nContext.Provider
+      value={{
+        t: translations,
+        locale,
+        dir,
+        setLocale,
+        supportedLocales: SUPPORTED_LOCALES,
+      }}
+    >
+      {children}
+    </I18nContext.Provider>
+  );
+}
+
+export const useTranslation = () => useContext(I18nContext);

apps/web/src/lib/api-errors.ts

@@ -0,0 +1,24 @@
+import type { TranslationKeys } from "@snapotter/shared";
+
+const API_ERROR_MAP: Record<string, string> = {
+  "Authentication required": "authRequired",
+  "Invalid credentials": "invalidCredentials",
+  "Invalid username or password": "invalidCredentials",
+  "Current password is incorrect": "currentPasswordIncorrect",
+  "No valid files uploaded": "noValidFiles",
+  "File too large": "fileTooLarge",
+  "Rate limit exceeded": "rateLimitExceeded",
+  "Processing failed": "processingFailed",
+  "Request timed out": "timeout",
+  "Connection error": "connectionError",
+  "Permission denied": "permissionDenied",
+  "Not found": "notFound",
+};
+
+export function translateApiError(apiMessage: string, t: TranslationKeys): string {
+  const key = API_ERROR_MAP[apiMessage];
+  if (key && key in t.errors) {
+    return t.errors[key as keyof typeof t.errors];
+  }
+  return apiMessage;
+}

apps/web/src/lib/format.ts

@@ -0,0 +1,27 @@
+export function format(template: string, values: Record<string, string | number>): string {
+  return template.replace(/\{(\w+)\}/g, (_, key) => String(values[key] ?? `{${key}}`));
+}
+
+export function plural(count: number, one: string, other: string): string {
+  return count === 1 ? one : other;
+}
+
+export function formatFileSize(bytes: number): string {
+  if (bytes < 1024) return `${bytes} B`;
+  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
+  if (bytes < 1024 * 1024 * 1024) return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
+  return `${(bytes / (1024 * 1024 * 1024)).toFixed(1)} GB`;
+}
+
+export function formatDate(date: Date | string, locale: string): string {
+  return new Date(date).toLocaleDateString(locale, {
+    year: "numeric",
+    month: "short",
+    day: "numeric",
+  });
+}
+
+export function formatDateTime(date: Date | string, locale: string): string {
+  const d = new Date(date);
+  return `${d.toLocaleDateString(locale, { year: "numeric", month: "short", day: "numeric" })} ${d.toLocaleTimeString(locale, { hour: "2-digit", minute: "2-digit" })}`;
+}

apps/web/src/lib/tool-i18n.ts

@@ -0,0 +1,15 @@
+import type { TranslationKeys } from "@snapotter/shared";
+
+export function getToolName(t: TranslationKeys, toolId: string, fallback: string): string {
+  const entry = (t.tools as Record<string, { name?: string }>)[toolId];
+  return entry?.name ?? fallback;
+}
+
+export function getToolDescription(t: TranslationKeys, toolId: string, fallback: string): string {
+  const entry = (t.tools as Record<string, { description?: string }>)[toolId];
+  return entry?.description ?? fallback;
+}
+
+export function getCategoryName(t: TranslationKeys, categoryId: string, fallback: string): string {
+  return (t.categories as Record<string, string>)[categoryId] ?? fallback;
+}