Firefox GitHub Repositories (2026) · Open Source Tools

Iceraven fork with a Zen Browser- inspired vertical tab sidebar for Android tablets (not affiliated with Zen Browser or Mozilla)

A Download Manager that speeds up your downloads

Chrome extension to return youtube dislikes

Firefox for iOS

Firefox privacy, security and anti-tracking: a comprehensive user.js template for configuration and hardening

This userscript for YouTube offers 250+ layout changes and features such as tab view, speed control, miniplayer support, export transcripts, square design, auto-theater mode, and much more—all easily customizable via settings panels.

Playwright that anti-bots cannot see, so no captchas: same API, anti-detect stealth headless Firefox, undetected fingerprint, bypass bot detection, Python web scraping and browser automation.

🖥🔋Web Extension starter to build "Write Once Run on Any Browser" extension

Firefox Profiler — Web app for Firefox performance analysis

Browser forensics tool for Google Chrome, other Chromium-based browsers, and Mozilla Firefox

Puppeteer for Python that anti-bots cannot see, so no captchas: same API, anti-detect stealth headless Firefox, undetected fingerprint, bypass bot detection, web scraping and browser automation.

Firefox CSS Theme/Style for manual customization

Toggl Track browser extension for Chrome and Firefox

🌸 Minimal, customizable startpage featuring the Catppuccin palettes

Adds an Ember tab to the browser's Developer Tools that allows you to inspect Ember objects in your application.

A browser extension that adds various web developer tools to a browser.

Changes the colour of Firefox theme to match the website’s appearance.

Measure and Optimize Web Performance

Browser extension and iOS app that spoofs your gps, geolocation & timezone, and auto-syncs to your VPN. Firefox, Chrome, Edge, Brave & Safari.

Search, group, move, and clean up tabs across browser windows with a keyboard-first workflow