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!
65,682 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.
56,881 users
Allow Right-Click
Re-enable the possibility to use the context menu on sites that overrides it
49,108 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
42,000 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.
40,165 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.
35,652 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.
32,651 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.
29,063 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
24,689 users
cookies.txt
Exports all cookies to a Netscape HTTP Cookie File, as used by curl, wget, and youtube-dl, among others.
23,487 users
SAML-tracer
A tool for viewing SAML and WS-Federation messages sent through the browser during single sign-on and single logout.
23,336 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.
23,098 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.
23,014 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
21,598 users
Font Finder (revived)
An easy-to-use font inspector to get CSS styles of the selected element
21,534 users
ImageAssistant Batch Image Downloader
An image extractor for sniffing, analyzing and batch downloading images from web page.
21,010 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.
19,662 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.
16,650 users
Google Lighthouse
Lighthouse is an open-source, automated tool for improving the performance, quality, and correctness of your web apps.
16,377 users
