Extensions
Explore powerful tools and features to customize Firefox and make the browser all your own.
Grammar and Spell Checker - LanguageTool
With this extension you can check text with the free style and grammar checker LanguageTool. It finds many errors that a simple spell checker cannot detect, like mixing up there/their, a/an, or repeating a word.
358,752 users
YouTube High Definition
YouTube High Definition is a powerful tool that automatically plays all YouTube videos in HD, changes video player size, offers auto-stop and mute, and much more.
164,325 users
Tomato Clock
Tomato Clock is a simple browser extension that helps with online time management.
36,828 users
AdGuard AdBlocker
Unmatched adblock extension against advertising and pop-ups. Blocks ads on Facebook, Youtube and all other websites.
1,093,788 users
LeechBlock NG
LeechBlock NG is a simple productivity tool designed to block those time-wasting sites that can suck the life out of your working day. All you need to do is specify which sites to block and when to block them.
69,755 users
SponsorBlock - Skip Sponsorships on YouTube
Easily skip YouTube video sponsors. When you visit a YouTube video, the extension will check the database for reported sponsors and automatically skip known sponsors. You can also report sponsors in videos. Other browsers: https://sponsor.ajay.app
452,181 users
Decentraleyes
Protects you against tracking through "free", centralized, content delivery. It prevents a lot of requests from reaching networks like Google Hosted Libraries, and serves local files to keep sites from breaking. Complements regular content blockers.
267,215 users
automaticDark - Time-Based Theme Changer
Automatically change Firefox's theme based on the time.
12,841 users
SoundFixer
Helps you fix annoying sound problems on sites like YouTube: audio in one channel only, too quiet or too loud. (Unfortunately, this extension does not work on all websites because of cross-domain issues — but it does work on YouTube!)
42,819 users
PopUpOFF
Removes and prevents popups, overlays and cookie notifications, other tools do not. Enjoy the original look of the internet.
27,658 users
Search by Image
A powerful reverse image search tool, with support for various search engines, such as Google, Bing, Yandex, Baidu and TinEye.
334,651 users