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.
33,464 users
JavaScript Switcher
A lightweight addon that adds a Toggle button in URL bar, for toggling JavaScript (on or off) individually per domain, and stores that for future visit. Works also with Firefox 57+.
6,122 users
Run JavaScript
Script injector for JavaScript and CSS!
1,660 users
JavaScript Toggle On and Off (WebExtension)
Toggle JavaScript engine on and off the easy way
13,408 users
JavaScript QR Code
Make QR Codes in pure JavaScript
519 users
Chrome Mask
Makes Firefox wear a mask to look like Chrome to websites that block Firefox otherwise.
50,510 users
NoScript Security Suite
The best security you can get in a web browser! Allow potentially malicious web content to run only from sites you trust. Protect yourself against XSS other web security exploits.
259,397 users
uBlock Origin
Finally, an efficient wide-spectrum content blocker. Easy on CPU and memory.
10,665,440 users
Greasemonkey
Customize the way a web page displays or behaves, by using small bits of JavaScript.
167,700 users
Script Runner
Script injector for JavaScript and CSS!
501 users
JavaScript Playground ⚡ Online JS Compiler
**Write and run JavaScript code instantly.** Skip the setup and open a distraction-free playground with a single click. Test functions, debug concepts, or learn new features right in a dedicated popup. just pure, instant JS code execution.
CanvasBlocker
Alters some JS APIs to prevent fingerprinting.
38,967 users
DuckDuckGo HTML Search (POST)
Adds DuckDuckGo HTML as a search engine for a non-JavaScript experience
258 users
HTML Comment Finder
Finds HTML, CSS and JavaScript comments in the current page
39 users
WebRequest Rules
Customize web requests by coding JavaScript yourself.
130 users
List all Links
List and search all text links, javascript, css, and image sources
207 users
WP Hive - A better WordPress Repository
Get useful metrics such as the impact on memory usage & pagespeed, PHP errors, warning, Javascript issues, PHP compatibility, latest WordPress version compatibility, database footprint, activation error, and more right from the WordPress repository
182 users
Turn Off the Lights for Firefox
The entire page will be fading to dark, so you can watch the videos as if you were in the cinema. Works for YouTube and Beyond. Dark mode for all websites. It works for all known video sites such as YouTube, Vimeo, Twitch, Dailymotion, Facebook, etc.
46,494 users
Customizer styles and scripts
Customize font size and styles of site. Extension give you able to change pages of sites on your choice, add custom javascript and run it on reload page, change font size, font color and any other styles with css syntax.
25 users
Mobile DevTools
an extension that adds Eruda developer tools to Firefox Android. Lets you use the console, inspect elements, and network monitor on your phone
3,965 users
Fucking JPEG
This addon makes sure you only get the image on Reddit/imgur/Tumblr media pages. "Just give me the fucking JPEG!"
558 users
Web Injector
Customize any website by injecting your own CSS and JavaScript. Includes tools for Dark Mode and RTL text fixing.
7 users
Location Guard
Hide your geographic location from websites. Report a fake location with the addition of random noise in order to protect your privacy. Per site settings with three configurable levels of accuracy or even the possibility to use a fixed location.
18,469 users
JS and CSS snippets for web
Run peristent JavaScript and CSS code snippets on any website.
3 users
HTML Runner
Run HTML, CSS, and JavaScript instantly in a new tab — no server, no build, no setup.