Easily override the browser's User-Agent string
Advanced Cookie Manager Requires Restart
A must have tool for Web Developers and Testers to Manage and monitor web cookies.
Export / Backup
Import / Restore
Available in English, French, Spanish, German and Italian languages.
Gives you a place to put all your add-on buttons without over-crowding the navigation bar.
Pearl Crescent Page Saver screenshot tool Requires Restart
Save an image of a web page (including Flash content) to a file. Web page screenshots may be captured interactively or from the command line. Options allow you to control the output format (PNG or JPEG), image file name, scaling, and much more.
Poster Requires Restart
A developer tool for interacting with web services and other web resources that lets you make HTTP requests, set the entity body, and content type. This allows you to interact with web services and inspect the results...
ICPBravo Access ICPBrasil and General PKI Extension.
Edit Cookies Requires Restart
This extension is now being partly maintained by Abine http://www.abine.com/.
New version of Edit Cookies by us is here: http://abine.com/edit_cookies.php
Send us any feedback about what you want:firstname.lastname@example.org.
Quickly and easily switch between popular user-agent strings.
Font Finder Requires Restart Featured
FontFinder is created for designers, developers and typographers. It allows a user to analyze the font information of any element on a page, copy any piece(s) of that information to the clipboard, and perform inline replacements to test new layouts.
Favorites (Selenium IDE) Requires Restart
A plugin for Selenium-IDE to have favorite test suites and open and execute the test suites with a single click
Auto Refresh Requires Restart
Auto Refresh will refresh or hard refresh any tab or group of tabs at individual or group intervals.
You can also customize your presets and save the ones you most use.
React Developer Tools is a tool that allows you to inspect a React tree, including the component hierarchy, props, state, and more. To get started, just open the Firefox devtools and switch to the React tab.
YSlow Requires Restart
YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages.
http://yslow.org is the official open source website.
Classic Toolbar Buttons Featured
'Classic Toolbar Buttons' add-on restores old toolbar button ui (known from Fx 4-7s small view, Fx 4-12s large view & Tb 5-14) for current Firefox, Thunderbird and Seamonkey versions.
Beta builds on versions page!
Empty Cache Button Requires Restart
Cache clearing made easy. One click.
Autofill Requires Restart
Autofill is a small but powerful add-on that serves one purpose: fill form fields automatically on page load. It is for people who just want a straightforward form filler without all the bells and whistles.
CacheViewer Requires Restart
This extenion is GUI Front-end of "about:cache"...
XPath Checker Requires Restart
An interactive editor for XPath expressions.