CloakBrowser

CloakBrowser is a stealth Chromium binary with fingerprint patches applied at the C++ source level, wrapped in a thin Python and JavaScript API that mirrors Playwright and Puppeteer. It's built for developers running browser automation, scraping, or AI agents that keep getting flagged by antibot systems like Cloudflare, FingerprintJS, or reCAPTCHA. Instead of patching Chromium at runtime with JavaScript injection or config flags (the approach used by playwright-stealth or undetected-chromedriver), CloakBrowser compiles the patches into the binary itself, so detection scripts see a browser that behaves like a real one because it is one.

Key features

• Source-level patches: 71 C++ patches covering canvas, WebGL, audio, fonts, GPU, screen properties, WebRTC, network timing, automation signals, and CDP input behavior, compiled into the Chromium binary rather than injected via JS.
• Drop-in API: swap the import from playwright to cloakbrowser and existing code runs unchanged. Works with Playwright and Puppeteer in both Python and JavaScript, plus a community-maintained .NET client.
• Humanize mode: a single humanize=True flag adds Bézier-curve mouse movement, per-character typing timing, and realistic scroll patterns to defeat behavioral detection.
• Proxy support: HTTP and native SOCKS5 proxies (including inline credentials), with geoip=True auto-detecting timezone and locale from the proxy's exit IP and spoofing WebRTC ICE candidates to match.
• Persistent contexts: launch_persistent_context() keeps cookies and localStorage across sessions and avoids incognito-mode detection.
• Auto-downloading binary: pip install or npm install fetches the right stealth Chromium build for your platform automatically, verified with a pinned Ed25519 signature.
• Free and Pro tiers: a free build (one concurrent session, GitHub sign-in) for testing, with paid tiers scaling to thousands of concurrent sessions and access to the newest patched binary.

Ideal use cases

• Web scraping behind antibot walls: sites protected by Cloudflare Turnstile, ShieldSquare, or FingerprintJS bot detection that block stock Playwright or Puppeteer sessions.
• AI agent browsing: agents built on frameworks like browser-use, Crawl4AI, Scrapling, Stagehand, or LangChain that need a browser indistinguishable from a human-driven one.
• QA and monitoring at scale: teams running headless checks or synthetic monitoring that get misclassified as bots and need consistent, unflagged sessions across local, Docker, and VPS environments.
• CAPTCHA score improvement: cases where you need a higher reCAPTCHA v3 score rather than a CAPTCHA-solving service, since CloakBrowser prevents challenges from appearing rather than solving them after the fact.
• Not a fit if: you need built-in proxy rotation or CAPTCHA-solving services, since CloakBrowser expects you to bring your own proxies and doesn't solve CAPTCHAs it can't avoid. It's also overkill for scraping sites with no bot detection at all, where stock Playwright works fine.

Installation

Install via pip or npm depending on your stack. The stealth Chromium binary (~200MB) downloads automatically on first run and is cached locally.

Python:

pip install cloakbrowser

JavaScript with Playwright:

npm install cloakbrowser playwright-core

JavaScript with Puppeteer:

npm install cloakbrowser puppeteer-core

.NET / C# (community-maintained):

dotnet add package CloakBrowser

Optional geoip support for auto-detecting timezone/locale from a proxy IP:

pip install 'cloakbrowser[geoip]'

Quick test without installing anything:

docker run --rm cloakhq/cloakbrowser cloaktest

Basic usage in Python:

from cloakbrowser import launch

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

To get the latest binary and more concurrent sessions, sign in for a free key or set a license:

cloakbrowser login
export CLOAKBROWSER_LICENSE_KEY=cb_xxxxxxxx