Dark Reader
Dark mode for every website. Take care of your eyes, use dark theme for night and daily browsing.
1,292,199 users
Ghostery – Privacy Ad Blocker
The best privacy tool and ad blocker extension for Firefox. Stop trackers, speed up websites and block ads everywhere including YouTube and Facebook.
1,003,422 users
Stylus
Redesign your favorite websites with Stylus, an actively developed and community driven userstyles manager. Easily install custom themes from popular online repositories, or create, edit, and manage your own personalized CSS stylesheets.
123,465 users
Chrome Mask
Makes Firefox wear a mask to look like Chrome to websites that block Firefox otherwise.
49,495 users
Tampermonkey
Tampermonkey is the world's most popular userscript manager.
765,025 users
ColorZilla
Advanced Eyedropper, Color Picker, Gradient Generator and other colorful goodies...
132,121 users
Cookie-Editor
Cookie-Editor lets you efficiently create, edit and delete a cookie for the current tab. Perfect for developing, quickly testing or even manually managing your cookies for your privacy.
109,169 users
Ruffle - Flash Emulator
Putting Flash back on the web. Designed to be easy to use, this extension will seamlessly enable you to play flash content, with no extra configuration required!
77,788 users
User-Agent Switcher
Easily override the browser's User-Agent string
61,424 users
Bato Image Auto-Fixer
Detect broken bato.to images and automatically fix them.
48,300 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.
46,701 users
WhatFont
A wrapper for Chengyin Liu's WhatFont tool
33,843 users
Disable JavaScript
Adds the ability to disable JavaScript for specific sites or specific tabs. You can customize the default JS state (on or off), the disable behavior (by domain or by tab) and much more.
31,877 users
Disable WebRTC
WebRTC leaks your actual IP addresses from behind your VPN, by default.
23,616 users
Google Lighthouse
Lighthouse is an open-source, automated tool for improving the performance, quality, and correctness of your web apps.
15,234 users
JavaScript Toggle On and Off (WebExtension)
Toggle JavaScript engine on and off the easy way
12,802 users
RESTED
A REST client for the rest of us
12,390 users
My IP Hider VPN
My IP Hider VPN is number one tool for hiding your IP and unblocking any web site! If your Firefox version is less then 55 please install older My IP Hider VPN from "Version History" (https://goo.gl/7ZQQjZ)
12,253 users
JSON Lite
Fast JSON viewer - highlights, shows items count/size, handles large files
10,298 users
Save Screenshot
Saves the current page as image file or copies it to clipboard.
10,171 users
Empty Cache Button
Cache clearing made easy. One click.
9,882 users
Proxy Toggle
Toggle between direct connection and a single proxy server via a toolbar icon.
9,738 users
ScriptCat
Everything can be scripted, allowing your browser to do more!
8,983 users
Emoji Cheatsheet
A reference for the codes to generate Emojis on popular sites like GitHub or Basecamp and Unicode characters for Twitter and Facebook. Search Emojis by name or view recently selected items. Emojis are automatically copied to the clipboard.
7,165 users
IPvFoo
Display the server IP address, with a realtime summary of IPv4, IPv6, and HTTPS information across all page elements.
6,921 users