Top FIREFOX GitHub Repositories & Tools (2026)

Playwright is a framework for Web Testing and Automation. It allows testing Chromium, Firefox and WebKit with a single API.

Welcome to a calmer internet

A simple zero-config tool to make locally trusted development certificates with any names you'd like.

Better Lyrics for YouTube Music - Enhance YouTube Music with beautiful time-synced lyrics, multilingual support, real-time translations and more ✨

A browser extension that redirects popular sites to alternative privacy friendly frontends

:cloud: Sync your bookmarks privately across browsers and devices

All of source code of Floorp 12, the most Advanced and Fastest Firefox derivative 🦊

The cross-browser extension framework.

JavaScript API for Chrome and Firefox

A customizable read mode web extension.

Firefox CSS Theme/Style for manual customization

Web extension that adds keyboard shortcuts to Google, YouTube, Github, Amazon, and others (Chrome/Firefox/Edge/Safari)

The first AI agent harness native to the browser. A browser extension that runs a full agent loop where you already work: it drives your tabs, spins up sandboxed compute (JS notebooks, WASM Linux VMs, client-side apps), and shares what it builds peer-to-peer. BYOK, no backend, no telemetry.

Translate BiliBili To English or to French, Russian, Japanse, and more.

m3u8 file downloader library and chrome & firefox extensions/add-on's

FireX Proxy is a browser extension built to unblock websites and provide private browsing.

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.

Firefox for iOS

Subscription-free unofficial Firefox VPN client for Android.

Turn any website into a native-like Android app