User-Agent Switcher
Easily override the browser's User-Agent string
63,605 users
Bato Image Auto-Fixer
Detect broken bato.to images and automatically fix them.
61,201 users
Allow Right-Click
Re-enable the possibility to use the context menu on sites that overrides it
54,361 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.
49,495 users
Redux DevTools
DevTools for Redux with actions history, undo and replay.
48,687 users
WhatFont
A wrapper for Chengyin Liu's WhatFont tool
37,006 users
Nimbus Screen Capture: Screenshot, Edit, Annotate
★ Used by Several Million users on different platforms ★ 1) Screen capture web pages 2) Selected regions 3) Whole browser window 4) Slack upload Edit screenshots. Save images as local files or Google Drive. Tools for Annotation. Upload and share
36,574 users
Selenium IDE
Selenium IDE is an integrated development environment for Selenium tests. It is implemented as a Firefox extension, and allows you to record, edit, and debug tests.
35,696 users
cookies.txt
Exports all cookies to a Netscape HTTP Cookie File, as used by curl, wget, and youtube-dl, among others.
34,335 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.
33,871 users
JavaScript-Java Bridge
A replacement for the Java Plugin so Java Applets without graphics continue to work on browsers that no longer support NPAPI plugins. Java's LiveConnect API is emulated — data & method calls can be exchanged, and Java can manipulate the webpage DOM.
30,249 users
WAVE Accessibility Extension
Evaluate web accessibility within the Firefox browser. When activated, the WAVE extension injects icons and indicators into your page to give feedback about accessibility and to facilitate manual evaluation.
27,277 users
CORS Everywhere
A firefox addon allowing the user to enable CORS everywhere by altering http responses. Report issues to the repository, with enough information to reproduce the problem: https://github.com/spenibus/cors-everywhere-firefox-addon/issues
23,899 users
SAML-tracer
A tool for viewing SAML and WS-Federation messages sent through the browser during single sign-on and single logout.
23,658 users
Stylish - Custom themes for any website
Stylish lets you customize any website with custom user styles (themes for websites). Choose from the largest userstyles library to change the color scheme, background, and skin for Google, Facebook, YouTube and many, many more sites.
23,523 users
Disable WebRTC
WebRTC leaks your actual IP addresses from behind your VPN, by default.
23,491 users
Assinatura Digital no Navegador
Realize Assinaturas Digitais no navegador.
22,222 users
Font Finder (revived)
An easy-to-use font inspector to get CSS styles of the selected element
20,461 users
Colorpick Eyedropper
A simple eye-dropper & color-picker tool allowing you to select color values from webpages. You will need to enable the add-on bar Firefox menu->Options->Add-on Bar OR View->Toolbars->Add-on Bar Then refresh the page.
20,244 users
JSONView
View JSON documents in the browser.
18,786 users
Media Converter and Muxer - Audio Tools
Easy to use video and audio converter and muxer written in WebExtension built on top of the well-known FFmpeg converter
18,140 users
Google Lighthouse
Lighthouse is an open-source, automated tool for improving the performance, quality, and correctness of your web apps.
16,800 users
User-Agent Switcher
Quickly and easily switch between popular user-agent strings.
16,552 users
Xdebug Helper for Firefox
This extension is very useful for PHP developers that are using PHP tools with Xdebug support like PHPStorm, Eclipse with PDT, Netbeans and MacGDBp or any other Xdebug compatible profiling tool like KCacheGrind, WinCacheGrind or Webgrind.
16,415 users
Yandex Search
Adds Yandex for search engines
16,157 users