CloakBrowser/README.md

Stealth Chromium that passes every bot detection test.

Not a patched config. Not a JS injection. A real Chromium binary with fingerprints modified at the C++ source level. Antibot systems score it as a normal browser — because it is a normal browser.

Cloudflare Turnstile — 3 live tests passing (headed mode, macOS)

Drop-in Playwright/Puppeteer replacement for Python and JavaScript.
Same API, same code — just swap the import. 3 lines of code, 30 seconds to unblock.

• 🔒 26 source-level C++ patches — not JS injection, not config flags
• 🛡️ CDP stealth built-in — uses Patchright to reduce Playwright's automation footprint
• 🎯 0.9 reCAPTCHA v3 score — human-level, server-verified
• ☁️ Passes Cloudflare Turnstile, FingerprintJS, BrowserScan — 30/30 tests
• 🔄 Drop-in replacement — works with Playwright (Python & JS) and Puppeteer (JS)
• 📦 pip install cloakbrowser or npm install cloakbrowser — binary auto-downloads, zero config
• 💸 Enterprise results, zero cost — anti-detect browsers charge $49–299/month for the same results. CloakBrowser is free

Python:

from cloakbrowser import launch

browser = launch()
page = browser.new_page()
page.goto("https://protected-site.com")  # no more blocks
browser.close()

JavaScript (Playwright):

import { launch } from 'cloakbrowser';

const browser = await launch();
const page = await browser.newPage();
await page.goto('https://protected-site.com');
await browser.close();

Also works with Puppeteer: import { launch } from 'cloakbrowser/puppeteer' (details)

Install

Python:

pip install cloakbrowser

JavaScript / Node.js:

# With Playwright
npm install cloakbrowser playwright-core

# With Puppeteer
npm install cloakbrowser puppeteer-core

On first run, the stealth Chromium binary is automatically downloaded (~200MB, cached locally).

Optional: Auto-detect timezone/locale from proxy IP:

pip install cloakbrowser[geoip]

Migrating from Playwright? One-line change:

- from playwright.sync_api import sync_playwright
- pw = sync_playwright().start()
- browser = pw.chromium.launch()
+ from cloakbrowser import launch
+ browser = launch()

page = browser.new_page()
page.goto("https://example.com")
# ... rest of your code works unchanged

⭐ Star to show support — Watch releases to get notified when new builds drop.

What's New in v0.3.4

• All 4 platforms — Linux x64, macOS arm64, macOS x64, and Windows x64 all on Chromium 145
• 26 fingerprint patches — 10 new patches since v142 (screen, device memory, audio, WebGL, auto-spoof, and more)
• Stealthy with zero flags — binary auto-generates a random fingerprint seed at startup. No configuration required
• Deterministic seeds — --fingerprint=seed produces the same identity across launches for session persistence
• Full stealth audit — every patch reviewed for detection vectors, multiple fixes shipped
• Timezone & locale from proxy IP — launch(proxy="...", geoip=True) auto-detects timezone and locale
• SHA-256 checksum verification — binary downloads are verified for integrity
• CDP hardening — audited and patched known automation detection vectors

See the full CHANGELOG.md for details.

Why CloakBrowser?

• Config-level patches break — playwright-stealth, undetected-chromedriver, and puppeteer-extra inject JavaScript or tweak flags. Every Chrome update breaks them. Antibot systems detect the patches themselves.
• CloakBrowser patches Chromium source code — fingerprints are modified at the C++ level, compiled into the binary. Detection sites see a real browser because it is a real browser.
• Two layers of stealth — C++ patches handle fingerprints (GPU, screen, UA, hardware reporting), while the Patchright driver defers Playwright's binding registration and randomizes internal world names. Most stealth tools only do one or the other.
• Same behavior everywhere — works identically local, in Docker, and on VPS. No environment-specific patches or config needed.
• Works with AI browser agents — drop-in stealth binary for browser-use, agent-browser, Claude computer use, and OpenAI Operator
• One line to switch — same Playwright API, no new abstractions, no CAPTCHA-solving services.

CloakBrowser doesn't solve CAPTCHAs — it prevents them from appearing. Antibot systems score it as a normal browser because it is a normal browser, just with your fingerprints instead of theirs. No CAPTCHA services, no proxy rotation built in — bring your own proxies, use the Playwright API you already know.

Test Results

All tests verified against live detection services. Last tested: Mar 2026 (Chromium 145).

Detection Service	Stock Playwright	CloakBrowser	Notes
reCAPTCHA v3	0.1 (bot)	0.9 (human)	Server-side verified
Cloudflare Turnstile (non-interactive)	FAIL	PASS	Auto-resolve
Cloudflare Turnstile (managed)	FAIL	PASS	Single click
ShieldSquare	BLOCKED	PASS	Production site
FingerprintJS bot detection	DETECTED	PASS	demo.fingerprint.com
BrowserScan bot detection	DETECTED	NORMAL (4/4)	browserscan.net
bot.incolumitas.com	13 fails	1 fail	WEBDRIVER spec only
deviceandbrowserinfo.com	6 true flags	0 true flags	isBot: false
navigator.webdriver	true	false	Source-level patch
navigator.plugins.length	0	5	Real plugin list
window.chrome	undefined	object	Present like real Chrome
UA string	HeadlessChrome	Chrome/145.0.0.0	No headless leak
CDP detection	Detected	Not detected	isAutomatedWithCDP: false
TLS fingerprint	Mismatch	Identical to Chrome	ja3n/ja4/akamai match
		30/30 passed

Proof

reCAPTCHA v3 score 0.9 — server-side verified (human-level)

Cloudflare Turnstile non-interactive challenge — auto-resolved

BrowserScan bot detection — NORMAL (4/4 checks passed)

FingerprintJS web-scraping demo — data served, not blocked

How It Works

CloakBrowser is a thin wrapper (Python + JavaScript) around a custom-built Chromium binary:

1. You install → pip install cloakbrowser or npm install cloakbrowser
2. First launch → binary auto-downloads for your platform (Chromium 145)
3. Every launch → Playwright or Puppeteer starts with our binary + stealth args
4. You write code → standard Playwright/Puppeteer API, nothing new to learn

The binary includes 26 source-level patches covering canvas, WebGL, audio, fonts, GPU, screen properties, hardware reporting, and automation signal removal.

These are compiled into the Chromium binary — not injected via JavaScript, not set via flags.

Binary downloads are verified with SHA-256 checksums to ensure integrity.

API

launch()

from cloakbrowser import launch

# Basic — headless, default stealth config
browser = launch()

# Headed mode (see the browser window)
browser = launch(headless=False)

# With proxy
browser = launch(proxy="http://user:pass@proxy:8080")

# With extra Chrome args
browser = launch(args=["--disable-gpu"])

# With timezone and locale (sets both binary flags and Playwright context)
browser = launch(timezone="America/New_York", locale="en-US")

# Auto-detect timezone/locale from proxy IP (requires: pip install cloakbrowser[geoip])
browser = launch(proxy="http://proxy:8080", geoip=True)

# Explicit timezone/locale always win over auto-detection
browser = launch(proxy="http://proxy:8080", geoip=True, timezone="Europe/London")

# Without default stealth args (bring your own fingerprint flags)
browser = launch(stealth_args=False, args=["--fingerprint=12345"])

Returns a standard Playwright Browser object. All Playwright methods work: new_page(), new_context(), close(), etc.

launch_async()

import asyncio
from cloakbrowser import launch_async

async def main():
    browser = await launch_async()
    page = await browser.new_page()
    await page.goto("https://example.com")
    print(await page.title())
    await browser.close()

asyncio.run(main())

launch_context()

Convenience function that creates browser + context with common options:

from cloakbrowser import launch_context

context = launch_context(
    user_agent="Custom UA",
    viewport={"width": 1920, "height": 1080},
    locale="en-US",
    timezone_id="America/New_York",
)
page = context.new_page()

Utility Functions

from cloakbrowser import binary_info, clear_cache, ensure_binary

# Check binary installation status
print(binary_info())
# {'version': '145.0.7632.109', 'platform': 'linux-x64', 'installed': True, ...}

# Force re-download
clear_cache()

# Pre-download binary (e.g., during Docker build)
ensure_binary()

JavaScript / Node.js API

CloakBrowser ships a TypeScript package with full type definitions. Choose Playwright or Puppeteer — same stealth binary underneath.

Playwright (default)

import { launch, launchContext } from 'cloakbrowser';

// Basic
const browser = await launch();

// With options
const browser = await launch({
  headless: false,
  proxy: 'http://user:pass@proxy:8080',
  args: ['--fingerprint=12345'],
  timezone: 'America/New_York',
  locale: 'en-US',
});

// Convenience: browser + context in one call
const context = await launchContext({
  userAgent: 'Custom UA',
  viewport: { width: 1920, height: 1080 },
  locale: 'en-US',
  timezoneId: 'America/New_York',
});
const page = await context.newPage();

Note: Each example above is standalone — not meant to run as one block.

All Python options work in JS: stealthArgs: false to disable defaults, geoip: true to auto-detect timezone/locale from proxy IP.

Puppeteer

Note: The Playwright wrapper is recommended for sites with reCAPTCHA Enterprise. Puppeteer's CDP protocol leaks automation signals that reCAPTCHA Enterprise can detect, causing intermittent 403 errors. This is a known Puppeteer limitation, not specific to CloakBrowser. Use Playwright for best results.

import { launch } from 'cloakbrowser/puppeteer';

const browser = await launch({ headless: true });
const page = await browser.newPage();
await page.goto('https://example.com');
await browser.close();

Utility Functions (JS)

import { ensureBinary, clearCache, binaryInfo } from 'cloakbrowser';

// Pre-download binary (e.g., during Docker build)
await ensureBinary();

// Check installation status
console.log(binaryInfo());

// Force re-download
clearCache();

Configuration

Env Variable	Default	Description
CLOAKBROWSER_BINARY_PATH	—	Skip download, use a local Chromium binary
CLOAKBROWSER_CACHE_DIR	~/.cloakbrowser	Binary cache directory
CLOAKBROWSER_DOWNLOAD_URL	cloakbrowser.dev	Custom download URL for binary
CLOAKBROWSER_AUTO_UPDATE	true	Set to false to disable background update checks
CLOAKBROWSER_SKIP_CHECKSUM	false	Set to true to skip SHA-256 verification after download

Fingerprint Management

The binary is stealthy by default — no flags needed. It auto-generates a random fingerprint seed at startup and spoofs all detectable values (GPU, hardware specs, screen dimensions, canvas, WebGL, audio, fonts). Every launch produces a fresh, coherent identity.

How fingerprinting works:

Scenario	What happens
No flags	Random seed auto-generated at startup. GPU, screen, hardware specs, and all noise patches are spoofed automatically. Fresh identity each launch.
--fingerprint=seed	Deterministic identity from the seed. Same seed = same fingerprint across launches. Use this for session persistence (returning visitor).
--fingerprint=seed + explicit flags	Explicit flags override individual auto-generated values. The seed fills in everything else.

The binary detects its platform at compile time — a macOS binary reports as macOS with Apple GPU, a Linux binary reports as Linux with NVIDIA GPU. The wrapper overrides this on Linux by passing --fingerprint-platform=windows, so sessions appear as Windows desktops (more common fingerprint, harder to cluster). Use --fingerprint-platform for cross-platform spoofing when running the binary directly.

Tip: Use a fixed seed when revisiting the same site. A random seed makes every session look like a different device — which can be suspicious when hitting the same site repeatedly from the same IP. For reCAPTCHA v3 Enterprise and similar scoring systems, a fixed seed produces a consistent fingerprint across sessions, making you look like a returning visitor:

browser = launch(args=["--fingerprint=12345"])

const browser = await launch({ args: ['--fingerprint=12345'] });

Default Fingerprint

Every launch() call sets these automatically. The wrapper applies platform-aware defaults — on Linux it spoofs as Windows for a more common fingerprint, on macOS it runs as a native Mac browser:

Flag	Linux/Windows Default	macOS Default	Controls
--fingerprint	Random (10000–99999)	Random (10000–99999)	Master seed for canvas, WebGL, audio, fonts, client rects
--fingerprint-platform	windows	macos	navigator.platform, User-Agent OS, GPU pool selection
--fingerprint-gpu-vendor	NVIDIA Corporation	Google Inc. (Apple)	WebGL UNMASKED_VENDOR_WEBGL
--fingerprint-gpu-renderer	NVIDIA GeForce RTX 3070	ANGLE (Apple, ANGLE Metal Renderer: Apple M3, Unspecified Version)	WebGL UNMASKED_RENDERER_WEBGL

The binary auto-generates hardware concurrency (8), device memory (8), and screen dimensions (1920x1080 on Windows/Linux, 1440x900 on macOS) from the seed. Override with explicit flags if needed.

Using the binary directly? It works out of the box with zero flags — the binary auto-spoofs everything. Pass --fingerprint=seed for a persistent identity, or use explicit flags like --fingerprint-gpu-renderer to override any auto-generated value.

Production tip: For better stealth at scale, pass your own GPU, screen, and hardware values instead of relying on defaults. Custom parameters make your sessions harder to cluster by anti-bot systems that look for uniform fingerprint profiles.

Additional Flags

Supported by the binary but not set by default — pass via args to customize:

Flag	Controls
--fingerprint-hardware-concurrency	navigator.hardwareConcurrency (auto-generated: 8)
--fingerprint-device-memory	navigator.deviceMemory in GB (auto-generated: 8)
--fingerprint-screen-width	Screen width (auto-generated: 1920 Win/Linux, 1440 macOS)
--fingerprint-screen-height	Screen height (auto-generated: 1080 Win/Linux, 900 macOS)
--fingerprint-brand	Browser brand: Chrome, Edge, Opera, Vivaldi
--fingerprint-brand-version	Brand version (UA + Client Hints)
--fingerprint-platform-version	Client Hints platform version
--fingerprint-location	Geolocation coordinates
--fingerprint-timezone	Timezone (e.g. America/New_York)
--fingerprint-taskbar-height	Override taskbar height (binary defaults: Win=48, Mac=95, Linux=0)
--fingerprint-fonts-dir	Path to cross-platform font directory
--enable-blink-features=FakeShadowRoot	Access closed shadow DOM elements

Note: All stealth tests were verified with the default fingerprint config above. Changing these flags may affect detection results — test your configuration before using in production.

Examples

# Pin a seed for a persistent identity
browser = launch(args=["--fingerprint=42069"])

# Full control — disable defaults, set everything yourself
browser = launch(stealth_args=False, args=[
    "--fingerprint=42069",
    "--fingerprint-platform=windows",
    "--fingerprint-gpu-vendor=NVIDIA Corporation",
    "--fingerprint-gpu-renderer=NVIDIA GeForce RTX 3070",
])

# Override GPU to look like a different machine
browser = launch(args=[
    "--fingerprint-gpu-vendor=Intel Inc.",
    "--fingerprint-gpu-renderer=Intel Iris OpenGL Engine",
])

Comparison

Feature	Playwright	playwright-stealth	undetected-chromedriver	Camoufox	CloakBrowser
reCAPTCHA v3 score	0.1	0.3-0.5	0.3-0.7	0.7-0.9	0.9
Cloudflare Turnstile	Fail	Sometimes	Sometimes	Pass	Pass
Patch level	None	JS injection	Config patches	C++ (Firefox)	C++ (Chromium)
Survives Chrome updates	N/A	Breaks often	Breaks often	Yes	Yes
Maintained	Yes	Stale	Stale	Unstable (2026 beta)	Active
Browser engine	Chromium	Chromium	Chrome	Firefox	Chromium
Playwright API	Native	Native	No (Selenium)	No	Native

Platforms

Platform	Chromium	Patches	Status
Linux x86_64	145	26	✅ Latest
macOS arm64 (Apple Silicon)	145	26	✅ Latest
macOS x86_64 (Intel)	145	26	✅ Latest
Windows x86_64	145	26	✅ Latest

The wrapper auto-downloads the correct binary for your platform.

macOS first launch: The binary is ad-hoc signed. On first run, macOS Gatekeeper will block it. Right-click the app → Open → click Open in the dialog. This is only needed once.

Examples

Python — see examples/:

• basic.py — Launch and load a page
• recaptcha_score.py — Check your reCAPTCHA v3 score
• stealth_test.py — Run against all detection services
• fingerprint_scan_test.py — Test against fingerprint-scan.com and CreepJS

JavaScript — see js/examples/:

• basic-playwright.ts — Playwright launch and load
• basic-puppeteer.ts — Puppeteer launch and load
• stealth-test.ts — Full 6-site detection test suite

Roadmap

Feature	Status
Linux x64 — Chromium 145 (26 patches)	✅ Released
macOS arm64/x64 — Chromium 145 (26 patches)	✅ Released
Windows x64 — Chromium 145 (26 patches)	✅ Released
JavaScript/Puppeteer + Playwright support	✅ Released
Fingerprint rotation per session	✅ Released
Built-in proxy rotation	📋 Planned

Docker

A ready-to-use Dockerfile is included. It installs system deps, the package, and pre-downloads the stealth binary during build:

docker build -t cloakbrowser .
docker run --rm cloakbrowser python examples/basic.py

The key steps in the Dockerfile:

1. System deps — Chromium requires ~15 shared libraries (libnss3, libgbm1, etc.)
2. pip install . — installs CloakBrowser + Playwright
3. ensure_binary() — downloads the stealth Chromium binary at build time (~200MB), so containers start instantly

To extend with your own script, just add a COPY + CMD:

FROM cloakbrowser
COPY your_script.py /app/
CMD ["python", "your_script.py"]

With a proxy (the most common production setup):

docker run --rm cloakbrowser python -c "
from cloakbrowser import launch
browser = launch(proxy='http://user:pass@proxy:8080')
page = browser.new_page()
page.goto('https://example.com')
print(page.title())
browser.close()
"

CloakBrowser works identically local, in Docker, and on VPS. No environment-specific config needed.

Note: If you run CloakBrowser inside a web server with uvloop (e.g., uvicorn[standard]), use --loop asyncio to avoid subprocess pipe hangs.

Headed Mode (for aggressive bot detection)

Some sites using advanced bot detection (e.g., DataDome, Cloudflare Turnstile) can detect headless mode even with our C++ patches. For these sites, run in headed mode with a virtual display:

# Install Xvfb (virtual framebuffer)
sudo apt install xvfb

# Start virtual display
Xvfb :99 -screen 0 1920x1080x24 &
export DISPLAY=:99

from cloakbrowser import launch

# Headed mode + residential proxy for maximum stealth
browser = launch(headless=False, proxy="http://your-residential-proxy:port")
page = browser.new_page()
page.goto("https://heavily-protected-site.com")  # passes DataDome, etc.
browser.close()

This runs a real headed browser rendered on a virtual display — no physical monitor needed. Combined with a residential proxy, this passes even the most aggressive detection services.

Tip: Datacenter IPs are often flagged by IP reputation databases regardless of browser fingerprint. For sites with strict bot detection, a residential proxy makes the difference.

Troubleshooting

Reddit or similar sites show CAPTCHA / "Prove your humanity"

Some sites (notably Reddit homepage) use HTTP/2 fingerprinting that detects Playwright's connection layer. Pass --disable-http2 to fall back to HTTP/1.1:

browser = launch(args=["--disable-http2"])

const browser = await launch({ args: ['--disable-http2'] });

Only use this flag for sites that require it — most sites work fine with HTTP/2.

Something not working? Make sure you're on the latest wrapper Older versions may use outdated stealth args or download an older binary:

pip install -U cloakbrowser    # Python
npm install cloakbrowser@latest # JavaScript

Binary download fails / timeout Set a custom download URL or use a local binary:

export CLOAKBROWSER_BINARY_PATH=/path/to/your/chrome

macOS: "App is damaged" or Gatekeeper blocks launch The binary is ad-hoc signed. macOS quarantines downloaded files. Run once to clear it:

xattr -cr ~/.cloakbrowser/chromium-*/Chromium.app

"playwright install" vs CloakBrowser binary You do NOT need playwright install chromium. CloakBrowser downloads its own binary. You only need Playwright's system deps:

patchright install-deps chromium

macOS: Blocked on some sites that pass on Linux

The macOS fingerprint profile has known inconsistencies that aggressive bot detection catches. If a site blocks you on macOS but works on Linux, switch to a Windows fingerprint profile by passing stealth_args=False and manually setting --fingerprint-platform=windows with matching GPU flags (see Fingerprint Management for the full flag list).

reCAPTCHA v3 scores are low (0.1–0.3)

Avoid page.wait_for_timeout() — it sends CDP protocol commands that reCAPTCHA detects. Use native sleep instead:

# Bad — sends CDP commands, reCAPTCHA detects this
page.wait_for_timeout(3000)

# Good — invisible to the browser
import time
time.sleep(3)

// Bad — sends CDP commands
await page.waitForTimeout(3000);

// Good — invisible to the browser
await new Promise(r => setTimeout(r, 3000));

Other tips for maximizing reCAPTCHA scores:

• Use Playwright, not Puppeteer — Puppeteer sends more CDP protocol traffic that reCAPTCHA detects (details)
• Use residential proxies — datacenter IPs are flagged by IP reputation, not browser fingerprint
• Spend 15+ seconds on the page before triggering reCAPTCHA — short visits score lower
• Space out requests — back-to-back grecaptcha.execute() calls from the same session get penalized. Wait 30+ seconds between pages with reCAPTCHA
• Use a fixed fingerprint seed for consistent device identity across sessions (see Fingerprint Management)
• Use page.type() instead of page.fill() for form filling — fill() sets values directly without keyboard events, which reCAPTCHA's behavioral analysis flags. type() with a delay simulates real keystrokes:

  page.type("#email", "user@example.com", delay=50)
  

• Minimize page.evaluate() calls before the reCAPTCHA check fires — each one sends CDP traffic

FAQ

Q: Is this legal? A: CloakBrowser is a browser. Using it is legal. What you do with it is your responsibility, just like with Chrome, Firefox, or any browser. We do not endorse violating website terms of service.

Q: How is this different from Camoufox? A: Camoufox patches Firefox. We patch Chromium. Chromium means native Playwright support, larger ecosystem, and TLS fingerprints that match real Chrome. Camoufox returned in early 2026 but is in unstable beta — CloakBrowser is production-ready.

Q: Will detection sites eventually catch this? A: Possibly. Bot detection is an arms race. Source-level patches are harder to detect than config-level patches, but not impossible. We actively monitor and update when detection evolves.

Q: Can I use my own proxy? A: Yes. Pass proxy="http://user:pass@host:port" to launch().

Links

• 📋 Changelog — CHANGELOG.md
• 🌐 Website — cloakbrowser.dev
• 🐛 Bug reports & feature requests — GitHub Issues
• 📦 PyPI — pypi.org/project/cloakbrowser
• 📦 npm — npmjs.com/package/cloakbrowser
• 📧 Contact — cloakhq@pm.me

License

• Wrapper code (this repository) — MIT. See LICENSE.
• CloakBrowser binary (compiled Chromium) — free to use, no redistribution. See BINARY-LICENSE.md.

Contributing

Issues and PRs welcome. If something isn't working, open an issue — we respond fast.