The User Agent Switcher extension adds a menu and a toolbar button to switch the user agent of a browser.
The Web Developer extension adds various web developer tools to the browser.
FoxyProxy is an advanced proxy management tool that completely replaces Firefox's limited proxying capabilities. For a simpler tool and less advanced configuration options, please use FoxyProxy Basic.
Use tamperdata to view and modify HTTP/HTTPS headers and post parameters...
A customizable mouse gestures extension which enables to execute various commands and user scripts with six types of gestures.
Personas are free, easy-to-install "skins" for Firefox. Personas Plus extends that built-in functionality to give you even more control and easier access to new, popular, and your own favorite Personas.
View HTTP headers of a page and while browsing.
Autofill Forms enables you to fill out web forms with one click.
Allows you to quickly switch to a different language (User Interface, Spell Checker Dictionary and Website content) in your Mozilla application.
Useful tools for the nightly tester.
Collections are groups of related add-ons that anyone can create and share.Explore Collections