CloakBrowser

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.

• 58 source-level C++ patches — canvas, WebGL, audio, fonts, GPU, screen, WebRTC, network timing, automation signals, CDP input behavior
• humanize=True — human-like mouse curves, keyboard timing, and scroll patterns. One flag, behavioral detection passes
• 0.9 reCAPTCHA v3 score — human-level, server-verified
• Passes Cloudflare Turnstile, FingerprintJS, BrowserScan — tested against 30+ detection sites
• Auto-updating binary — background update checks, always on the latest stealth build
• pip install cloakbrowser or npm install cloakbrowser — binary auto-downloads, zero config
• Free and open source — no subscriptions, no usage limits

Try it now — no install needed:

docker run --rm cloakhq/cloakbrowser cloaktest

Python:

from cloakbrowser import launch

browser = launch()
page = browser.new_page()
page.goto("https://example.com")
browser.close()

JavaScript (Playwright):

import { launch } from 'cloakbrowser';

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

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

For sites with anti-bot protection, add a residential proxy and these flags:

browser = launch(
    proxy="http://user:pass@residential-proxy:port",  # residential IP, not datacenter
    geoip=True,       # match timezone + locale to proxy IP
    headless=False,    # some sites detect headless even with C++ patches
    humanize=True,     # human-like mouse, keyboard, scroll
)

const browser = await launch({
    proxy: 'http://user:pass@residential-proxy:port',
    geoip: true,
    headless: false,
    humanize: true,
});

See Troubleshooting for site-specific issues (FingerprintJS, Kasada, reCAPTCHA).

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.

Browser Profile Manager

Self-hosted alternative to Multilogin, GoLogin, and AdsPower. Create browser profiles with unique fingerprints, proxies, and persistent sessions. Launch and interact with them in your browser via noVNC.

docker run -p 8080:8080 -v cloakprofiles:/data cloakhq/cloakbrowser-manager

Open http://localhost:8080. Create a profile. Click Launch. Done.

→ CloakBrowser Manager — free, open source (MIT)

---

Latest: v0.3.31 (Chromium 146.0.7680.177.5)

• 58 fingerprint patches — rendering consistency improvements across Linux and Windows, corrected GPU/display/graphics parameters to match stock Chrome 146 profiles
• Windows native GPU passthrough — real hardware values pass through directly instead of being spoofed, matching real browser behavior
• HTTP proxy inline credentials — new network-layer support for proxies with inline authentication
• extension_paths — load Chrome extensions in all launch functions
• Humanize actionability — auto-wait for visible, enabled, stable elements before humanized actions
• Per-call human_config — override humanize settings on individual method calls
• Composable JS helpers — buildLaunchOptions() and humanizeBrowser() for custom Playwright integrations
• Native SOCKS5 proxy — proxy="socks5://user:pass@host:port" works directly in all launch functions, Python + JS. QUIC/HTTP3 tunnels through SOCKS5 via UDP ASSOCIATE
• Proxy signal removal — DNS/connect/SSL timing zeroed, proxy cache headers stripped, Proxy-Connection header leak removed
• Chromium 146 upgrade — rebased all patches from 145.0.7632.x to 146.0.7680.177
• WebRTC IP spoofing — --fingerprint-webrtc-ip=auto resolves your proxy's exit IP and spoofs WebRTC ICE candidates. Auto-injected when using geoip=True (no extra network call)
• humanize=True — one flag makes all mouse, keyboard, and scroll interactions behave like a real user. Bézier curves, per-character typing, realistic scroll patterns
• Stealthy with zero flags — binary auto-generates a random fingerprint seed at startup. No configuration required
• Timezone & locale from proxy IP — launch(proxy="...", geoip=True) auto-detects timezone and locale
• Persistent profiles — launch_persistent_context() keeps cookies and localStorage across sessions, bypasses incognito detection

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.
• Source-level stealth — C++ patches handle fingerprints (GPU, screen, UA, hardware reporting) at the binary level. No JavaScript injection, no config-level hacks. Most stealth tools only patch at the surface.
• Same behavior everywhere — works identically local, in Docker, and on VPS. No environment-specific patches or config needed.
• Works with AI agents and automation frameworks — drop-in stealth for browser-use, Crawl4AI, Scrapling, Stagehand, LangChain, Selenium, and more. See integrations.

CloakBrowser doesn't solve CAPTCHAs — it prevents them from appearing. No CAPTCHA-solving 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: Apr 2026 (Chromium 146).

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/146.0.0.0	No headless leak
CDP detection	Detected	Not detected	isAutomatedWithCDP: false
TLS fingerprint	Mismatch	Identical to Chrome	ja3n/ja4/akamai match
		Tested against 30+ detection sites

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

deviceandbrowserinfo.com behavioral bot detection — "You are human!" with humanize=True (24/24 signals passed)

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	Active
Browser engine	Chromium	Chromium	Chrome	Firefox	Chromium
Playwright API	Native	Native	No (Selenium)	No	Native

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 146)
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 58 source-level patches covering canvas, WebGL, audio, fonts, GPU, screen properties, WebRTC, network timing, hardware reporting, automation signal removal, and CDP input behavior mimicking.

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 (HTTP or SOCKS5)
browser = launch(proxy="http://user:pass@proxy:8080")
browser = launch(proxy="socks5://user:pass@proxy:1080")

# With proxy dict (bypass, separate auth fields)
browser = launch(proxy={"server": "http://proxy:8080", "bypass": ".google.com", "username": "user", "password": "pass"})

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

# With timezone and locale (sets binary flags — no detectable CDP emulation)
browser = launch(timezone="America/New_York", locale="en-US")

# Auto-detect timezone/locale from proxy IP (requires: pip install cloakbrowser[geoip])
# Also auto-injects --fingerprint-webrtc-ip to prevent WebRTC IP leaks (no extra cost)
# Note: makes HTTP calls through your proxy to resolve exit IP (ipify.org, checkip.amazonaws.com)
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")

# WebRTC IP spoofing only (no geoip dep needed — resolves exit IP via HTTP call through proxy)
browser = launch(proxy="http://proxy:8080", args=["--fingerprint-webrtc-ip=auto"])

# Explicit WebRTC IP (no network call)
browser = launch(proxy="http://proxy:8080", args=["--fingerprint-webrtc-ip=1.2.3.4"])

# Human-like mouse, keyboard, and scroll behavior
browser = launch(humanize=True)

# With slower, more deliberate movements
browser = launch(humanize=True, human_preset="careful")

# 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 in one call with user agent, viewport, locale, and timezone:

from cloakbrowser import launch_context

context = launch_context(
    user_agent="Custom UA",
    viewport={"width": 1920, "height": 1080},
    locale="en-US",
    timezone="America/New_York",
)
page = context.new_page()
page.goto("https://protected-site.com")
context.close()

Extra kwargs are forwarded to Playwright's browser.new_context() — use this for storage_state, permissions, extra_http_headers, etc. without needing a persistent profile folder:

from cloakbrowser import launch_context

# Restore a saved session (cookies, localStorage) from a JSON file
context = launch_context(storage_state="state.json")
page = context.new_page()
page.goto("https://example.com")
# Save state back for next run
context.storage_state(path="state.json")
context.close()

launch_context_async()

Async counterpart to launch_context(). Same signature and kwargs forwarding:

import asyncio
from cloakbrowser import launch_context_async

async def main():
    ctx = await launch_context_async(storage_state="state.json")
    page = await ctx.new_page()
    await page.goto("https://example.com")
    await ctx.storage_state(path="state.json")
    await ctx.close()

asyncio.run(main())

launch_persistent_context()

Same as launch_context(), but with a persistent user profile. Cookies, localStorage, and cache persist across sessions.

Use this when you need to:

• Stay logged in across runs (cookies/sessions survive restarts)
• Bypass incognito detection (some sites flag empty, ephemeral profiles)
• Load Chrome extensions (extensions only work from a real user data dir)
• Build natural browsing history (cached fonts, service workers, IndexedDB accumulate over time, making the profile look more realistic)

from cloakbrowser import launch_persistent_context

# First run — creates the profile
ctx = launch_persistent_context("./my-profile", headless=False)
page = ctx.new_page()
page.goto("https://protected-site.com")
ctx.close()  # profile saved

# Next run — cookies, localStorage restored automatically
ctx = launch_persistent_context("./my-profile", headless=False)

# Load Chrome extensions
ctx = launch_persistent_context(
    "./my-profile",
    headless=False,
    extension_paths=["./my-extension"],
)

Supports all the same options as launch_context(): proxy, user_agent, viewport, locale, timezone, color_scheme, geoip, extension_paths.

Async version: launch_persistent_context_async().

Storage quota and detection tradeoff: By default, the binary normalizes storage quota to pass FingerprintJS, which blocks persistent contexts that report non-incognito quota values. This means detection services that penalize incognito mode (like BrowserScan's notPrivate check, -10 points) will still flag it. If your target site penalizes incognito but doesn't use FingerprintJS, set a higher quota to appear as a regular profile:

ctx = launch_persistent_context("./my-profile", args=["--fingerprint-storage-quota=5000"])

Quota setting	FingerprintJS	BrowserScan notPrivate
Default (auto, ~500MB)	PASS	-10 (flagged as incognito)
--fingerprint-storage-quota=5000	May trigger detection	PASS (appears non-incognito)

CLI

Pre-download the binary or check installation status from the command line:

python -m cloakbrowser install      # Download binary with progress output
python -m cloakbrowser info         # Show version, path, platform
python -m cloakbrowser update       # Check for and download newer binary
python -m cloakbrowser clear-cache  # Remove cached binaries

Utility Functions

from cloakbrowser import binary_info, clear_cache, ensure_binary

# Check binary installation status
print(binary_info())
# {'version': '146.0.7680.177.5', '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, launchPersistentContext } 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',
  humanize: true,
});

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

// Persistent profile — cookies/localStorage survive restarts, avoids incognito detection
const ctx = await launchPersistentContext({
  userDataDir: './chrome-profile',
  headless: false,
  proxy: 'http://user:pass@proxy:8080',
});

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();

Human Behavior

Pass humanize=True to make all mouse, keyboard, and scroll interactions indistinguishable from real users. All Playwright calls (page.click(), page.fill(), page.type(), page.mouse.*, page.keyboard.*, Locator API) and Puppeteer calls (page.click(), page.type(), page.mouse.*, page.keyboard.*, ElementHandle API) are automatically replaced with human-like equivalents. No code changes needed.

browser = launch(humanize=True)
page = browser.new_page()
page.goto("https://example.com")
page.locator("#email").fill("user@example.com")  # per-character timing, thinking pauses
page.locator("button[type=submit]").click()       # Bézier curve, realistic aim point

// Playwright
import { launch } from 'cloakbrowser';
const browser = await launch({ humanize: true });

// Puppeteer
import { launch } from 'cloakbrowser/puppeteer';
const browser = await launch({ humanize: true });

What changes:

Interaction	Default	With humanize=True
Mouse movement	Instant teleport	Bézier curve with easing and slight overshoot
Clicks	Instant	Realistic aim point + hold duration
Keyboard	Instant fill	Per-character timing, thinking pauses, occasional typos with self-correction
Scroll	Jump	Accelerate → cruise → decelerate micro-steps
fill()	Instant value set	Clears existing content, types character by character

Presets — default (normal speed) or careful (slower, more deliberate, idle micro-movements between actions):

browser = launch(humanize=True, human_preset="careful")

const browser = await launch({ humanize: true, humanPreset: 'careful' });

Custom config — override any parameter:

browser = launch(humanize=True, human_config={
    "mistype_chance": 0.05,              # 5% typo rate with self-correction
    "typing_delay": 100,                 # slower typing (ms per character)
    "idle_between_actions": True,        # micro-movements between clicks
    "idle_between_duration": [0.3, 0.8], # idle duration range (seconds)
})

const browser = await launch({
    humanize: true,
    humanConfig: {
        mistype_chance: 0.05,
        typing_delay: 100,
        idle_between_actions: true,
        idle_between_duration: [0.3, 0.8],
    }
});

Access the original un-patched Playwright page at page._original if you need raw speed for a specific call.

Note (Playwright): Always use page.click(selector), page.type(selector, text), page.hover(selector), or page.locator(selector).* — these go through the full humanize pipeline. Avoid page.query_selector() — ElementHandle objects bypass all patches, so mouse movement teleports, keyboard events fire without timing, and scroll has no human curve.

Note (Puppeteer): Both selector-based methods (page.click(), page.type()) and ElementHandle methods (el.click(), el.type()) are fully humanized. page.$(), page.$$(), and page.waitForSelector() return patched handles automatically.

Contributed by @evelaa123 — full Playwright and Puppeteer API coverage.

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
CLOAKBROWSER_GEOIP_TIMEOUT_SECONDS	5	Max seconds for GeoIP resolution before continuing without it

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

The binary auto-generates everything else from the seed: GPU, hardware concurrency, device memory, and screen dimensions. Each seed produces a unique, consistent fingerprint. 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.

Additional Flags

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

Flag	Controls
--fingerprint-gpu-vendor	WebGL UNMASKED_VENDOR_WEBGL (auto-generated from seed + platform)
--fingerprint-gpu-renderer	WebGL UNMASKED_RENDERER_WEBGL (auto-generated from seed + platform)
--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-locale	Locale (e.g. en-US)
--fingerprint-storage-quota	Override storage quota in MB — affects storage.estimate(), storageBuckets, and legacy webkit APIs. Auto-normalized when --fingerprint is set
--fingerprint-taskbar-height	Override taskbar height (binary defaults: Win=48, Mac=95, Linux=0)
--fingerprint-fonts-dir	Path to directory containing target-platform fonts (see Font Setup on Linux)
--fingerprint-webrtc-ip	WebRTC ICE candidate IP replacement. Use auto to resolve from proxy exit IP (makes an HTTP call through the proxy), or pass an explicit IP. Auto-injected when geoip=True
--fingerprint-noise=false	Disable noise injection (canvas, WebGL, audio, client rects) while keeping the deterministic fingerprint seed active
--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.

Font Setup on Linux

Required for aggressive anti-bot sites (Kasada, Akamai). These systems render emoji on a hidden canvas and hash the pixel output. Minimal Linux environments (Docker, cloud VMs) often lack emoji and extended fonts, producing hashes that don't match any real browser. Install standard font packages to fix this:

sudo apt install -y fonts-noto-color-emoji fonts-freefont-ttf fonts-unifont \
    fonts-ipafont-gothic fonts-wqy-zenhei fonts-tlwg-loma-otf

The Docker image (cloakhq/cloakbrowser) ships with these pre-installed. If you run the binary directly on a Linux server or in a custom Docker image, install them manually.

Optional: Windows fonts for CreepJS font enumeration. The packages above fix anti-bot canvas checks but won't improve your CreepJS font score. For that, you need actual Windows fonts (Segoe UI, Calibri, Bahnschrift, etc.) from a Windows machine's C:\Windows\Fonts\ directory — ttf-mscorefonts-installer only has old XP-era fonts and isn't enough.

mkdir -p ~/.local/share/fonts/windows
cp /path/to/windows/fonts/*.ttf ~/.local/share/fonts/windows/
cp /path/to/windows/fonts/*.TTF ~/.local/share/fonts/windows/
fc-cache -f  # mandatory for manually copied fonts

browser = launch(
    args=["--fingerprint-fonts-dir=/home/user/.local/share/fonts/windows"],
)

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",
])

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

Examples

Python — see examples/:

• basic.py — Launch and load a page
• persistent_context.py — Persistent profile with cookie/localStorage persistence
• recaptcha_score.py — Check your reCAPTCHA v3 score
• stealth_test.py — Run against 6 detection sites
• 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 — Run against 6 detection sites

Framework Integrations

CloakBrowser works with any framework that uses Playwright or Chromium:

# Option 1: Framework launches our binary directly (Selenium, Stagehand, UC)
from cloakbrowser.download import ensure_binary
from cloakbrowser.config import get_default_stealth_args
binary_path = ensure_binary()          # auto-downloads if needed
stealth_args = get_default_stealth_args()  # all fingerprint flags

# Option 2: CloakBrowser launches first, framework connects via CDP (browser-use, Crawl4AI, Scrapling)
from cloakbrowser import launch_async
browser = await launch_async(args=["--remote-debugging-port=9242"])
# Connect your framework to http://127.0.0.1:9242 — all stealth flags are set
# Note: humanize requires the wrapper (see below)

Humanize over CDP: Stealth fingerprint patches work automatically over CDP, but humanize=True is a wrapper-level feature. If you connect to CloakBrowser via CDP from a separate script, import the patching functions to add humanization:

import { patchBrowser, resolveConfig } from 'cloakbrowser/human';
patchBrowser(browser, resolveConfig('default'));

Framework	Stars	Language	Example
browser-use	70K	Python	browser_use_example.py
Crawl4AI	58K	Python	crawl4ai_example.py
Crawlee	8.6K	Python	crawlee_example.py
Scrapling	21K	Python	scrapling_example.py
Stagehand	21K	TypeScript	stagehand.ts
LangChain	100K+	Python	langchain_loader.py
Selenium	—	Python	selenium_example.py
undetected-chromedriver	12K	Python	undetected_chromedriver.py
agent-browser	—	Shell	agent_browser.sh

Deployment Integrations

Platform	Example
AWS Lambda	aws_lambda/ — One-shot scrapes in Lambda (container image)

Platforms

Platform	Chromium	Patches	Status
Linux x86_64	146	58	✅ Latest
Linux arm64 (RPi, Graviton)	146	58	✅
macOS arm64 (Apple Silicon)	145	26	✅
macOS x86_64 (Intel)	145	26	✅
Windows x86_64	146	58	✅ 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.

Docker

Pre-built image on Docker Hub — no install, no setup.

Quick test

docker run --rm cloakhq/cloakbrowser cloaktest

Run a script

# Inline script
docker run --rm cloakhq/cloakbrowser python -c "
from cloakbrowser import launch
browser = launch()
page = browser.new_page()
page.goto('https://example.com')
print(page.title())
browser.close()
"

# Mount your own script
docker run --rm -v ./my_script.py:/app/my_script.py cloakhq/cloakbrowser python my_script.py

# With a proxy
docker run --rm cloakhq/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()
"

CDP server mode

Start a persistent stealth browser and connect to it remotely via Chrome DevTools Protocol:

docker run -d --name cloak -p 127.0.0.1:9222:9222 cloakhq/cloakbrowser cloakserve

Then connect from your host machine:

from playwright.sync_api import sync_playwright

pw = sync_playwright().start()
browser = pw.chromium.connect_over_cdp("http://localhost:9222")
page = browser.new_page()
page.goto("https://example.com")
print(page.title())
browser.close()

If your framework needs a direct WebSocket endpoint, fetch Chrome's discovery document and use the rewritten webSocketDebuggerUrl. The URL points back through cloakserve so the CDP proxy can keep per-seed routing intact:

curl http://localhost:9222/json/version | jq -r .webSocketDebuggerUrl
# ws://localhost:9222/devtools/browser/<browser-id>

curl 'http://localhost:9222/json/version?fingerprint=11111' | jq -r .webSocketDebuggerUrl
# ws://localhost:9222/fingerprint/11111/devtools/browser/<browser-id>

When cloakserve runs behind a reverse proxy or TLS terminator, forward the public host/protocol headers so generated WebSocket URLs use the address clients can actually reach:

proxy_set_header Host $host;
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Proto $scheme;

With those headers, /json/version returns public endpoints such as wss://cdp.example.com/fingerprint/11111/devtools/browser/<browser-id> instead of an internal container host.

Pass extra flags to the browser:

# With proxy
docker run -d --name cloak -p 127.0.0.1:9222:9222 cloakhq/cloakbrowser \
  cloakserve --proxy-server=http://proxy:8080

# Headed mode (renders to Xvfb inside container)
docker run -d --name cloak -p 127.0.0.1:9222:9222 cloakhq/cloakbrowser \
  cloakserve --headless=false

Stop the server:

docker stop cloak && docker rm cloak

Security: CDP gives full control over the browser (execute JS, read pages, access files). The examples bind to 127.0.0.1 so only your machine can connect. Never expose port 9222 to the public internet without additional authentication.

Docker Compose

services:
  cloakbrowser:
    image: cloakhq/cloakbrowser
    command: cloakserve
    restart: unless-stopped
    ports:
      - "127.0.0.1:9222:9222"
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:9222/json/version"]
      interval: 30s
      timeout: 5s
      retries: 3
      start_period: 10s

Per-connection fingerprint seeds — run multiple browser identities from a single container. Each unique seed spawns a separate Chrome process with its own fingerprint:

# Each seed gets unique canvas noise, client rects, and other browser signals
b1 = pw.chromium.connect_over_cdp("http://localhost:9222?fingerprint=11111")
b2 = pw.chromium.connect_over_cdp("http://localhost:9222?fingerprint=22222")

# Full identity control via query params
b3 = pw.chromium.connect_over_cdp(
    "http://localhost:9222?fingerprint=33333"
    "&timezone=Asia/Tokyo&locale=ja-JP&platform=macos"
    "&hardware-concurrency=4&device-memory=8"
)

# Auto-detect timezone/locale from proxy exit IP
b4 = pw.chromium.connect_over_cdp(
    "http://localhost:9222?fingerprint=44444"
    "&proxy=http://proxy:8080&geoip=true"
)

Supported query params: fingerprint, timezone, locale, platform, platform-version, brand, brand-version, gpu-vendor, gpu-renderer, hardware-concurrency, device-memory, screen-width, screen-height, proxy, geoip. Same seed reuses the same process (first connection's params win). No seed = shared default process (backward compatible). Check active processes at GET / (returns JSON with PIDs, ports, and connection counts).

Persistent profiles — mount a volume to keep cookies and sessions across container restarts:

docker run --rm -v ./my-profile:/profile cloakhq/cloakbrowser python -c "
from cloakbrowser import launch_persistent_context
ctx = launch_persistent_context('/profile')
page = ctx.new_page()
page.goto('https://example.com')
ctx.close()
"

Run again with the same volume — cookies, localStorage, and cache are restored automatically.

Resource usage: ~190MB RAM idle, ~280MB with 3 tabs. ~30MB per additional tab.

Extend with your own image

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

Building your own image from pip — use python -m cloakbrowser install to download the binary during build with visible progress:

FROM python:3.12-slim
RUN pip install cloakbrowser && python -m cloakbrowser install
COPY your_script.py /app/
CMD ["python", "/app/your_script.py"]

Building from source — a Dockerfile is also included if you prefer to build your own image:

docker build -t cloakbrowser .

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.

Troubleshooting

---

Still getting blocked on aggressive sites (DataDome, Turnstile)?

Some sites detect headless mode even with our C++ patches. 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. Combine with the recommended config below for maximum stealth.

---

Recommended config for anti-bot sites

Most blocks come from missing one of these three things, not from browser fingerprint detection:

browser = launch(
    proxy="http://your-residential-proxy:port",  # residential IP — datacenter IPs get blocked by reputation alone
    geoip=True,      # matches timezone + locale to proxy exit IP (without this: UTC + en-US = bot signal)
    headless=False,   # headed mode — some sites detect headless even with C++ patches
    humanize=True,    # human-like mouse, keyboard, scroll behavior
)

const browser = await launch({
    proxy: 'http://your-residential-proxy:port',
    geoip: true,
    headless: false,
    humanize: true,
});

If your proxy supports SOCKS5, use it for better compatibility — SOCKS5 tunnels raw TCP, avoiding HTTP CONNECT issues that some proxies have with HTTP/2:

browser = launch(proxy="socks5://user:pass@proxy:1080", geoip=True, headless=False, humanize=True)

If you're still blocked after this, check the font setup below.

---

Detected by FingerprintJS?

FingerprintJS (demo.fingerprint.com/playground) checks multiple signals. Each detection has a specific cause:

Detection	Cause	Fix
nodriver / bad bot	IP reputation or missing flags	Residential proxy + config below
Browser tampering	Noise injection detected by ML	--fingerprint-noise=false
Virtual machine	Screen dimensions don't match viewport	--fingerprint-screen-width/height matching viewport
Incognito	Storage quota normalized to ~500MB	Expected tradeoff — see below

Config that passes FPJS (verified on v0.3.30, Linux + Windows):

browser = launch(
    headless=False,
    proxy="http://user:pass@residential-proxy:port",
    geoip=True,
    args=[
        "--fingerprint-noise=false",          # prevents tampering detection
        "--fingerprint-screen-width=1920",    # match your viewport
        "--fingerprint-screen-height=1080",
    ],
)

const browser = await launch({
    headless: false,
    proxy: 'http://user:pass@residential-proxy:port',
    geoip: true,
    args: [
        '--fingerprint-noise=false',
        '--fingerprint-screen-width=1920',
        '--fingerprint-screen-height=1080',
    ],
});

For persistent contexts (launch_persistent_context / launchPersistentContext), also add --fingerprint-storage-quota=500 to the args.

Storage quota tradeoff: The binary normalizes storage quota to ~500MB to pass FPJS, but this makes the session look like incognito to other detection services (e.g. BrowserScan's notPrivate check, -10 points). Setting --fingerprint-storage-quota=5000 passes incognito checks but may trigger FPJS. You can't satisfy both simultaneously — choose based on what your target site checks. See the storage quota tradeoff table for details.

---

Blocked on Kasada / Akamai sites despite correct config?

On minimal Linux environments, missing font packages cause canvas emoji rendering to produce hashes that anti-bot systems don't recognize. This is the most common cause of blocks on aggressive sites after proxy, geoip, and headed mode are already set up correctly.

Install the font packages listed in Font Setup on Linux above.

---

Sites challenge fresh sessions but work after first visit

Some sites challenge first-time visitors with no cookies over HTTP/2. This affects all Chromium browsers, not just CloakBrowser. Use a persistent profile to warm up cookies once, then reuse across sessions:

from cloakbrowser import launch_persistent_context

# First run: warm up with --disable-http2
ctx = launch_persistent_context("./profile", args=["--disable-http2"])
page = ctx.new_page()
page.goto("https://example.com")  # warms up cookies
ctx.close()

# Future runs — no --disable-http2 needed
ctx = launch_persistent_context("./profile")
page = ctx.new_page()
page.goto("https://example.com")  # passes with saved cookies

import { launchPersistentContext } from 'cloakbrowser';

// First run: warm up with --disable-http2
let ctx = await launchPersistentContext({ userDataDir: './profile', args: ['--disable-http2'] });
let page = await ctx.newPage();
await page.goto('https://example.com');
await ctx.close();

// Future runs — no --disable-http2 needed
ctx = await launchPersistentContext({ userDataDir: './profile' });

For stateless/ephemeral use cases, launch(args=["--disable-http2"]) forces HTTP/1.1 which bypasses the check. Only use this flag for sites that require it — most work fine with HTTP/2. If your proxy supports SOCKS5, use proxy="socks5://user:pass@host:port" instead — SOCKS5 bypasses HTTP CONNECT entirely.

---

Something not working? Make sure you're on the latest version

Older versions may use outdated stealth args or download an older binary:

pip install -U cloakbrowser    # Python
npm install cloakbrowser@latest # JavaScript
docker pull cloakhq/cloakbrowser:latest  # Docker

---

Binary download fails / timeout

Set a custom download URL or use a local binary:

export CLOAKBROWSER_BINARY_PATH=/path/to/your/chrome

---

New update broke something? Roll back to the previous version

Install a specific wrapper version to downgrade both the wrapper and the binary it downloads:

pip install cloakbrowser==0.3.21              # Python
npm install cloakbrowser@0.3.21               # JavaScript
docker pull cloakhq/cloakbrowser:0.3.21       # Docker

Each wrapper version pins its own binary version, so downgrading the wrapper automatically gets you the matching binary on next launch.

---

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:

playwright 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).

---

Site detects incognito / private browsing mode

By default, launch() opens an incognito context. Some sites penalize this. Use launch_persistent_context() to get a real profile with cookie persistence:

from cloakbrowser import launch_persistent_context

ctx = launch_persistent_context("./my-profile", headless=False)

If the site still flags incognito, raise the storage quota to appear as a regular browsing session. See the storage quota tradeoff for details on how this affects different detection services.

---

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:

• Try the Patchright backend — suppresses additional CDP automation signals at the Playwright protocol layer. Install with pip install cloakbrowser[patchright], then use launch(backend="patchright") or set CLOAKBROWSER_BACKEND=patchright globally. Note: Patchright breaks proxy auth and add_init_script — only use it if you're still seeing low scores after trying the steps above
• 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 built on open-source Chromium. We do not condone illegal use. Automating systems without authorization, credential stuffing, and account creation abuse are expressly prohibited. See BINARY-LICENSE.md for full terms.

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" or proxy="socks5://user:pass@host:port" to launch(). Both HTTP and SOCKS5 proxies are supported natively.

Roadmap

Feature	Status
Linux x64 — Chromium 146 (58 patches)	✅ Released
macOS arm64/x64 — Chromium 145 (26 patches)	✅ Released
Windows x64 — Chromium 146 (58 patches)	✅ Released
JavaScript/Puppeteer + Playwright support	✅ Released
Fingerprint rotation per session	✅ Released
Built-in proxy rotation	📋 Planned

Links

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

Security

All releases are signed for supply chain verification.

# Verify GPG signature (binary release tag)
gpg --keyserver keyserver.ubuntu.com --recv-keys C60C0DDC9D0DE2DD
git verify-tag chromium-v146.0.7680.177.5

# Verify GitHub binary attestation (Sigstore)
gh attestation verify cloakbrowser-linux-x64.tar.gz --repo CloakHQ/cloakbrowser

# Verify Docker image signature (Cosign/Sigstore)
cosign verify \
  --certificate-identity-regexp "https://github.com/CloakHQ/CloakBrowser/" \
  --certificate-oidc-issuer "https://token.actions.githubusercontent.com" \
  cloakhq/cloakbrowser:latest

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.

Contributors

• @evelaa123 — humanize behavior, persistent contexts, Windows fix
• @yahooguntu — persistent contexts
• @kitiho — null viewport fix
• @eofreternal — humanConfig type fix, humanized method option types, iframe pointer-events fix
• @manaskarra — iframe scope fix for humanized frame actions, GeoIP timeout guard
• @Youhai020616 — SOCKS5 credential encoding logging
• @AlexTech314 — AWS Lambda integration, cold-start hardening
• @dgtlmoon — graceful pw.stop() cleanup
• @zackycodes — Chrome extension loading
• @aaronjmars — security fixes (shell injection, dep bumps)
• @Seryiza — Nix/NixOS flake
• @245678000000 — package-lock sync
• @honor2030 — cloakserve WebSocket origin guard, composable JS launch helpers
• @sparanoid — Docker Xvfb lock cleanup
• @0xlally — security reports (cloakserve path traversal, WebSocket origin bypass)