CloakBrowser: a stealth Chromium binary with C++ source-level patches to bypass bot detection

What it solves

CloakBrowser provides a stealthy Chromium binary designed to bypass advanced bot detection systems (like Cloudflare Turnstile, reCAPTCHA v3, and FingerprintJS) that typically block automated browsers. Unlike traditional stealth plugins that inject JavaScript or modify configurations, CloakBrowser modifies the Chromium source code at the C++ level to ensure the browser behaves and looks like a genuine human user to detection scripts.

How it works

It is a thin wrapper for Python, JavaScript, and .NET that manages a custom-built Chromium binary. This binary contains dozens of source-level C++ patches that modify fingerprints for GPU, WebGL, audio, fonts, and network timing. It also includes a humanize flag that simulates realistic human mouse movements (using Bézier curves), keyboard typing, and scrolling patterns. The wrapper integrates seamlessly as a drop-in replacement for Playwright and Puppeteer APIs.

Who it’s for

It is designed for developers building AI agents, web scrapers, QA automation, and monitoring tools that need to access websites with strict anti-bot protections without being blocked or triggering CAPTCHAs.

Highlights

• Source-level Stealth: 58+ C++ patches compiled into the binary to prevent detection of automation signals.
• Drop-in Replacement: Compatible with Playwright and Puppeteer APIs, requiring minimal code changes to migrate.
• Human-like Interaction: Built-in behavioral simulation for mouse, keyboard, and scrolling.
• High Success Rates: Verified to pass reCAPTCHA v3 (0.9 score) and Cloudflare Turnstile.
• Automatic Configuration: Auto-downloads the binary and can automatically detect timezone and locale based on the proxy IP.
• Persistent Profiles: Supports persistent user data directories to bypass incognito detection and maintain sessions.