diff --git a/tests/e2e/content-aware-resize.spec.ts b/tests/e2e/content-aware-resize.spec.ts
new file mode 100644
index 00000000..d59691cb
--- /dev/null
+++ b/tests/e2e/content-aware-resize.spec.ts
@@ -0,0 +1,173 @@
+import path from "node:path";
+import { expect, test } from "./helpers";
+
+function fixturePath(name: string): string {
+  return path.join(process.cwd(), "tests", "fixtures", name);
+}
+
+async function uploadFile(page: import("@playwright/test").Page, filePath: string) {
+  const fileChooserPromise = page.waitForEvent("filechooser");
+  const dropzone = page.locator("[class*='border-dashed']").first();
+  await dropzone.click();
+  const fileChooser = await fileChooserPromise;
+  await fileChooser.setFiles(filePath);
+  await page.waitForTimeout(500);
+}
+
+async function enableContentAware(page: import("@playwright/test").Page) {
+  const toggle = page
+    .getByRole("switch", { name: "Content-aware" })
+    .or(
+      page
+        .locator("button[role='switch'][aria-checked]")
+        .filter({ hasText: "" })
+        .locator("..")
+        .filter({ hasText: "Content-aware" })
+        .locator("button[role='switch']"),
+    );
+  const sw = page.locator("button[role='switch']").first();
+  if ((await sw.getAttribute("aria-checked")) !== "true") {
+    await sw.click();
+  }
+  await expect(sw).toHaveAttribute("aria-checked", "true");
+}
+
+test.describe("Content-Aware Resize", () => {
+  test("content-aware toggle reveals seam carving controls", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+
+    await expect(page.getByText("Content-aware")).toBeVisible();
+
+    // Controls hidden before toggle
+    await expect(page.getByText("Resize to square")).not.toBeVisible();
+    await expect(page.getByText("Protect faces")).not.toBeVisible();
+
+    await enableContentAware(page);
+
+    // Controls visible after toggle
+    await expect(page.getByText("Resize to square")).toBeVisible();
+    await expect(page.getByText("Protect faces")).toBeVisible();
+    await expect(page.getByText("Smoothing")).toBeVisible();
+    await expect(page.getByText("Edge sensitivity")).toBeVisible();
+  });
+
+  test("standard resize tabs hidden when content-aware is active", async ({
+    loggedInPage: page,
+  }) => {
+    await page.goto("/resize");
+
+    // Standard tabs visible before toggle
+    await expect(page.getByRole("button", { name: "Custom" })).toBeVisible();
+
+    await enableContentAware(page);
+
+    // Standard tabs hidden
+    await expect(page.getByRole("button", { name: "Custom" })).not.toBeVisible();
+  });
+
+  test("submit disabled without file", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+    await enableContentAware(page);
+
+    await expect(page.getByTestId("resize-submit")).toBeDisabled();
+  });
+
+  test("submit disabled without dimensions or square mode", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+    await enableContentAware(page);
+    await uploadFile(page, fixturePath("test-200x150.png"));
+
+    // Width and height are empty, square is unchecked - submit should be disabled
+    const widthInput = page.locator("input[placeholder='Auto']").first();
+    await widthInput.fill("");
+    const heightInput = page.locator("input[placeholder='Auto']").nth(1);
+    await heightInput.fill("");
+
+    await expect(page.getByTestId("resize-submit")).toBeDisabled();
+  });
+
+  test("submit enables with width specified", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+    await enableContentAware(page);
+    await uploadFile(page, fixturePath("test-200x150.png"));
+
+    const widthInput = page.locator("input[placeholder='Auto']").first();
+    await widthInput.fill("150");
+
+    await expect(page.getByTestId("resize-submit")).toBeEnabled();
+  });
+
+  test("submit enables with square mode checked", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+    await enableContentAware(page);
+    await uploadFile(page, fixturePath("test-200x150.png"));
+
+    await page.getByText("Resize to square").click();
+
+    await expect(page.getByTestId("resize-submit")).toBeEnabled();
+  });
+
+  test("square mode disables width and height inputs", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+    await enableContentAware(page);
+
+    await page.getByText("Resize to square").click();
+
+    const widthInput = page.locator("input[placeholder='Auto']").first();
+    const heightInput = page.locator("input[placeholder='Auto']").nth(1);
+
+    await expect(widthInput).toBeDisabled();
+    await expect(heightInput).toBeDisabled();
+  });
+
+  test("smoothing slider has correct range", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+    await enableContentAware(page);
+
+    const slider = page.locator("#blur-radius");
+    await expect(slider).toHaveAttribute("min", "0");
+    await expect(slider).toHaveAttribute("max", "20");
+  });
+
+  test("edge sensitivity slider has correct range", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+    await enableContentAware(page);
+
+    const slider = page.locator("#sobel-threshold");
+    await expect(slider).toHaveAttribute("min", "1");
+    await expect(slider).toHaveAttribute("max", "20");
+  });
+
+  test("PNG - content-aware resize processes and shows result", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+    await enableContentAware(page);
+    await uploadFile(page, fixturePath("test-200x150.png"));
+
+    const widthInput = page.locator("input[placeholder='Auto']").first();
+    await widthInput.fill("150");
+
+    await page.getByTestId("resize-submit").click();
+
+    // Either succeeds with download or fails with error (caire not installed)
+    const download = page.getByTestId("resize-download");
+    const error = page.getByText(/failed|not available|not found|error/i);
+
+    await expect(download.or(error)).toBeVisible({ timeout: 120_000 });
+  });
+
+  test("HEIC input with content-aware resize", async ({ loggedInPage: page }) => {
+    await page.goto("/resize");
+    await enableContentAware(page);
+    await uploadFile(page, fixturePath("test-200x150.heic"));
+
+    const widthInput = page.locator("input[placeholder='Auto']").first();
+    await widthInput.fill("150");
+
+    await page.getByTestId("resize-submit").click();
+
+    const download = page.getByTestId("resize-download");
+    const error = page.getByText(/failed|not available|not found|error/i);
+
+    await expect(download.or(error)).toBeVisible({ timeout: 120_000 });
+  });
+});