Proxy SwitchyOmega
Manage and switch between multiple proxies quickly & easily.
58,292 users
Redux DevTools
DevTools for Redux with actions history, undo and replay.
57,507 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
50,704 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!
50,104 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.
47,576 users
Allow Right-Click
Re-enable the possibility to use the context menu on sites that overrides it
42,390 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.
38,187 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.
37,574 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.
37,040 users
WhatFont
A wrapper for Chengyin Liu's WhatFont tool
36,392 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).
36,122 users
Disable WebRTC
WebRTC leaks your actual IP addresses from behind your VPN, by default.
30,693 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
27,267 users
JSONView
View JSON documents in the browser.
26,773 users
User-Agent Switcher
Quickly and easily switch between popular user-agent strings.
26,710 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
25,883 users
SAML-tracer
A tool for viewing SAML and WS-Federation messages sent through the browser during single sign-on and single logout.
25,207 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.
23,630 users
ImageAssistant Batch Image Downloader
An image extractor for sniffing, analyzing and batch downloading images from web page.
23,033 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.
22,535 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.
22,282 users
Font Finder (revived)
An easy-to-use font inspector to get CSS styles of the selected element
22,143 users
ModHeader
Add and modify the HTTP request headers and response headers. Use ModHeader to: - Add / modify request and response headers - Add / modify cookies - Multi-profile support - Filtering based on URL, tab, or window - Export and share profiles
21,352 users
Autofill
A form filler, form recovery, text snippets, and automation tool all in one.
20,079 users
SeoQuake SEO extension
Accelerate your SEO efforts on the fly. SEOquake is a free plugin for browsers that provides you with key SEO metrics for a specific page, along with other useful tools such as SEO Audit and many others.
19,016 users