🛡️ Stealth Guard

Advanced browser fingerprinting protection for MV2-compatible browsers (Opera, Brave, Vivaldi, Edge)

Stealth Guard is a privacy-focused browser extension that protects against various fingerprinting techniques used to track users across the web. It provides comprehensive defense against canvas, WebGL, font, audio, and other fingerprinting methods while maintaining website compatibility.

✨ Features

🔒 Fingerprinting Protection

Protection	Description
🌍 Proxy	Masks your IP address by routing traffic through SOCKS4/5 or HTTP/HTTPS proxy servers
🌐 User-Agent	Spoofs browser User-Agent string in both HTTP headers and JavaScript
🕐 Timezone	Spoofs timezone information (configurable, default: UTC+1)
📡 WebRTC	Prevents IP address leaks through WebRTC connections
🎨 Canvas	Adds imperceptible noise to canvas data exports, preventing canvas fingerprinting
📐 ClientRects	Adds noise to element bounding rectangle measurements
🔤 Font	Randomizes font measurement values to prevent font enumeration
🔊 AudioContext	Injects noise into audio frequency data to prevent audio fingerprinting
🕹️ WebGL	Spoofs GPU vendor/renderer information and adds noise to WebGL buffers
🎮 WebGPU	Spoofs WebGPU adapter limits and buffer operations

🚀 Additional Features

• 🔌 SOCKS5/HTTP/HTTPS Proxy Support - Route traffic through proxy servers with per-profile configuration
• 🗺️ Domain-based Routing Engine - PAC-based domain routing is supported in core proxy logic (UI route editor is not currently exposed)
• ✅ Global & Per-Feature Allowlists - Whitelist sites globally or per protection feature
• 🎯 Wildcard Domain Patterns - Support for *.example.com and webmail.* patterns
• ☁️ Cloudflare Turnstile Compatibility - Auto-detects Turnstile challenges and temporarily disables User-Agent spoofing
• 🔔 Real-time Notifications - Optional alerts when fingerprinting attempts are blocked
• 💾 Export/Import Settings - Backup and restore your configuration
• 📦 No Build System Required - Pure vanilla JavaScript, ready to use

📥 Installation

🔧 Manual Installation (Developer Mode)

1. Download or clone this repository
2. Open your browser's extension page:
   • Opera: Navigate to opera://extensions/
   • Brave: Navigate to brave://extensions/
   • Vivaldi: Navigate to vivaldi://extensions/
   • Edge: Navigate to edge://extensions/
3. Enable Developer mode (toggle in top-right corner)
4. Click Load unpacked
5. Select the extension folder

📖 Usage

⚡ Quick Access (Popup)

Click the Stealth Guard icon in your browser toolbar to:

• Toggle protection on/off globally
• Enable/disable individual protection features
• Select User-Agent presets (macOS Safari, Chrome, Windows Edge, iPhone, Android)
• Choose timezone presets
• View proxy status
• See which protections were triggered on the current page

⚙️ Advanced Settings

Open Advanced Settings from the popup to access:

• Per-feature allowlists
• Proxy profile management
• Proxy active profile + bypass list
• WebGL presets (Apple, Pixel 4, Surface Pro 7)
• Export/import configuration
• WebRTC policy settings

🖱️ Context Menu

Right-click on any webpage to quickly add or remove the current domain from allowlists.

🔧 Configuration

🎯 Domain Patterns

Stealth Guard supports flexible domain matching:

Pattern	Matches
example.com	example.com and www.example.com
*.example.com	All subdomains (sub.example.com, deep.sub.example.com)
webmail.*	Any domain starting with webmail. (webmail.company.com)
*pattern*	Generic wildcard matching (foo-localhost-bar)

🌐 User-Agent Presets

Choose from predefined User-Agent strings:

• macOS Safari
• macOS Chrome
• Windows Edge
• iPhone Safari
• Android Chrome

🕐 Timezone Presets

Available timezones:

• UTC-8 (Los Angeles)
• UTC-7 (Denver)
• UTC-6 (Chicago)
• UTC-5 (New York)
• UTC+0 (London)
• UTC+1 (Paris) - Default
• UTC+2 (Athens)
• UTC+3 (Istanbul)
• UTC+4 (Dubai)
• UTC+7 (Jakarta)
• UTC+8 (Shanghai)
• UTC+9 (Tokyo)

🧪 Testing Your Protection

Visit these sites to verify your fingerprinting protection:

• https://browserleaks.com/ - Comprehensive fingerprint testing
• https://webbrowsertools.com/ - AudioContext testing
• https://amiunique.org/ - Browser uniqueness analysis
• https://dnscheck.tools/ - WebRTC and DNS leak testing

🏗️ Technical Details

📁 Architecture

background.js              → Runtime orchestrator (webRequest UA spoofing, WebRTC policy, proxy lifecycle, message hub)
    ↓
content-scripts/
  injector.js              → Session-cached bootstrap + MAIN-world protection injection
    ↓
lib/
  config.js                → Config defaults + merge/persistence helpers
  domainFilter.js          → Domain extraction + wildcard allowlist matching
  proxy.js                 → Proxy mode/PAC generation and profile helpers
  storage.js               → Promise wrapper for chrome.storage.local

📋 Manifest Version

This extension intentionally uses Manifest V2 for maximum API compatibility. Key features like webRequestBlocking and synchronous header modification require MV2 and are restricted or impossible in Manifest V3.

Warning

Because of Manifest V2, this extension will no longer work on standard versions of Google Chrome due to the MV2 phase-out. It is designed for browsers that maintain support for Manifest V2 extensions (such as Opera, Brave, Vivaldi, and potentially Enterprise Edge).

🔐 Permissions

Permission	Purpose
storage	Save user settings
privacy	Control WebRTC IP handling policy
proxy	Configure SOCKS5/HTTP proxy
webRequest / webRequestBlocking	Modify User-Agent headers
declarativeNetRequest	Legacy compatibility cleanup for prior UA rule path
tabs	Detect active tab for context menu
contextMenus	Right-click menu integration
notifications	Fingerprint detection alerts

🔒 Privacy

Stealth Guard:

• Does not collect any user data
• Does not phone home (except for optional proxy location checks via ipinfo.io)
• Stores all settings locally in browser storage
• Is fully open source - audit the code yourself

🌐 Browser Compatibility

Browser	Support	Notes
Opera	✅ Full support	Built-in functionality maintains MV2 support
Brave	✅ Full support	Built-in functionality maintains MV2 support
Vivaldi	✅ Full support	Built-in functionality maintains MV2 support
Microsoft Edge	⚠️ Limited	Supported via enterprise policies (until phase-out)
Google Chrome	❌ Unsupported	Standard Chrome has phased out Manifest V2

Note: Firefox uses a different extension format and is not currently supported.

🤝 Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

👤 Author

okasi - okasi.me - GitHub

🙏 Acknowledgments

• Inspired by the need for better privacy tools in an increasingly tracked web
• Thanks to the browser fingerprinting research community for documenting these techniques