Laboratory (Content Security Policy / CSP Toolkit)
Because good website security shouldn't only be available to mad scientists! Laboratory is a WebExtension that helps you generate a Content Security Policy (CSP) header for your website.
1,591 users
Siteimprove Accessibility Checker
Jumpstart your web accessibility efforts directly in Firefox. Is your web page accessible for everyone? Assess the accessibility of your web pages conveniently in Mozilla Firefox browser with the Siteimprove Accessibility Checker.
1,555 users
Xdebug-ext
Adds a simple button to inject a Xdebug cookie. Compatible with Firefox 57+ (Quantum). It is a port of "The easiest Xdebug" Addon by Nikita Nikitin, which is not compatible with WebExtensions.
1,546 users
Print PDF
Print any Webpage to PDF. No server or third-party processing. Uses built-in Firefox converter.
1,542 users
Load Time
Adds an icon to the address bar to provide load time information of the current page.
1,527 users
Website IP
Simple add-on that displays the current website IP address without a third party service. Converting the current tabs domain name to IPv4 & IPv6 via DNS lookup.
1,523 users
FullPage Capture
Full-page screenshot to clipboard. No tracking, no servers a fully oss solution
1,519 users
Extension source viewer
View source code of Firefox add-ons and Chrome extensions (crx/nex/xpi) from addons.mozilla.org, the Chrome Webstore and elsewhere, with CRX Viewer (crxviewer).
1,503 users
BugHerd: Visual Feedback & Bug Tracking Tool
Screenshots for the point and click bug tracker
1,501 users
Open Graph Preview
Shows approximately what users will see if this webpage is shared on websites that uses OG tags to display a preview. Let you detect if no Open Graph Tags are set on your webpage ! The shown preview is inspired from the Facebook one.
1,501 users
tweak: mock and modify HTTP requests
tweak allows you to mock and modify HTTP requests without leaving the browser
1,488 users
ClaudeCodeBrowser
ClaudeCodeBrowser enables AI-powered browser automation through the Claude Code CLI. It allows Claude to interact with web pages by taking screenshots, clicking elements, typing text, scrolling, and navigating - all controlled via a local MCP server.
1,488 users
DevTools Media Panel
DevTools panel that displays technical details about media elements and webrtc on the current page; intended primarily for web developers to understand media playback issues on their sites, and for users to provide more informative bug reports.
1,484 users
Page Edit
Make any webpage into a content editable document and modify it via toolbar popup!
1,454 users
HighlightAll
Automatically highlight and count all occurrences of a word by selecting it. Custom mode option provides multiple highlighting feature with customizable colors and can also display search markers beside the scrollbar.
1,453 users
WP Theme Detector and Plugins Detector
Detects the theme and plugins used in WordPress and display information about them. For sites using wordpress an icon will appear - right hand side of the address bar.
1,431 users
Live editor for CSS, Less & Sass - Magic CSS
Live preview of CSS/Less/Sass code changes. Auto-save file, autocomplete, convert Less/Sass to CSS, beautify, minify, CSS reloader, linter, ...
1,428 users
Open in MS Edge™ Browser
Open current page, link, or all tabs in the Microsoft Edge™ browser
1,419 users
(Animated) Nyan Cat Progress Bar for YouTube™
Nyan Cat Progress Bar for YouTube™ ~~ [Animated] ~~
1,416 users
CSS Reloader
CSS Reloader is an extension that allows you to reload all the CSS of any site without you have to reload the page itself.
1,409 users
