Dark Reader
Dark mode for every website. Take care of your eyes, use dark theme for night and daily browsing.
1,179,512 users
AdGuard AdBlocker
Unmatched adblock extension against advertising and pop-ups. Blocks ads on Facebook, Youtube and all other websites.
1,079,213 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.
163,963 users
Google Search Fixer
Override the user-agent string presented to Google Search pages to receive the search experience shown to Chrome.
126,674 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.
69,635 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!)
37,981 users
Tomato Clock
Tomato Clock is a simple browser extension that helps with online time management.
36,710 users
Tampermonkey
Tampermonkey is the world's most popular userscript manager.
715,486 users
I don't care about cookies
Get rid of cookie warnings from almost all websites!
321,546 users
Greasemonkey
Customize the way a web page displays or behaves, by using small bits of JavaScript.
199,050 users
Absolute Enable Right Click & Copy
Force Enable Right Click & Copy
91,770 users
User-Agent Switcher
Easily override the browser's User-Agent string
66,542 users
Cookie Quick Manager
An addon to manage cookies (view, search, create, edit, remove, backup, restore, protect from deletion and much more). Firefox 57+ is supported.
64,742 users
Popup Blocker Ultimate
Best Pop-up Blocker for Firefox. (Best in Rating, Performance, This addon does NOT collect user's data same as Poper Blocker)If your Firefox version is not 57+ please install version 8.1 from Official website.
62,190 users
Adblock for Youtube™
Popular Adblock for Youtube™ Extension: Removes the video ads from Youtube™. Thanks to all AdBlock supporters!
49,863 users
RESTClient, a debugger for RESTful web services.
RESTClient has been completely rewritten for compatible with Firefox 57. Some functions are still missing (OAuth & OAuth 2.0 authentication).
35,125 users
Mate Translate – translator, dictionary
Your all-in-one translator for web pages, highlighted text & Netflix subtitles. Translate and learn words in 103 languages.
35,085 users
uBlacklist
Blocks sites you specify from appearing in Google search results
32,187 users
Youtube Audio
Stream just the audio from YouTube to save bandwidth and battery life
31,101 users
h264ify
Makes YouTube stream H.264 videos instead of VP8/VP9 videos
26,559 users
10ten Japanese Reader (Rikaichamp)
Quickly translate Japanese by hovering over words. Formerly released as Rikaichamp.
22,429 users
BlockTube
YouTube™ Content Blocker Block channels and videos from YouTube™ Fast and easy
19,529 users
Redirector
Automatically redirects to user-defined urls on certain pages
16,834 users
Impulse Blocker
Block distracting websites. Just list the sites you want Impulse Blocker to pause or completely avoid.
16,573 users
JSON Lite
Fast JSON viewer - highlights, shows items count/size, handles large files
15,213 users