Firefox Addon GitHub Repositories (2026) · Open Source Tools

Web Extension for saving a faithful copy of a complete web page in a single HTML file

:cloud: Sync your bookmarks privately across browsers and devices

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

Yet another awesome browser extension for switching search engines, search everything (selection text / image / link / find in page) on any engine with a simple right click or a variety of menus and shortcuts. Build with React & Material-UI. (WIP).

The cross-browser extension framework.

Blocks specific sites from appearing in Google search results

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

Dark Reader Chrome and Firefox extension

Extension that adds word-by-word/syllable lyrics feature to YouTube Music and Apple Music (experimental), it's lightweight & good, this extension also fix apple music web lyrics

📚 A customizable dictionary extension that supports double-click lookups in 20+ languages, 1000+ dictionaries, text-to-speech, translation and Anki integration.

Free, open-source IDM alternative for macOS, Windows, Linux and Android, with iOS testing builds. Up to 256 adaptive connections on desktop and Android, resumable downloads, queues, BitTorrent, video downloads and browser extensions.

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

An awesome browser extension that reads aloud webpage content with one click

Chrome extension to return youtube dislikes

Integrating ChatGPT into your browser deeply, everything you need is here

Reddit Enhancement Suite

Scrobble music all around the web!

Browser extension which gives you more control over your Twitter timeline and adds missing features and UI improvements - for desktop and mobile

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

Use native tab discarding method to automatically reduce memory usage of inactive tabs