Blocks annoying video ads on YouTube, Facebook ads, banners and much more.
Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).
The easy way to download and convert Web videos from hundreds of YouTube-like sites.
This works also for audio and picture galleries.
Protect your privacy. See who's tracking your web browsing and block them with Ghostery.
Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.
Automate Firefox. Record and replay repetitious work. If you love the Firefox web browser, but are tired of repetitive tasks like visiting the same sites every days, filling out forms, and remembering passwords, then iMacros for Firefox is the soluti...
The User Agent Switcher extension adds a menu and a toolbar button to switch the user agent of a browser.
Lightbeam is a Firefox add-on that enables you to see the first and third party sites you interact with on the Web. Using interactive visualizations, Lightbeam shows you the relationships between these third parties and the sites you visit.
Cookies when you need them, not when others need them to track you - gets rid of a site's cookies and LocalStorage as soon as you close its tabs. Protects against trackers and zombie-cookies. Trustworthy services can be whitelisted.
Advanced Eyedropper, Color Picker, Gradient Generator and other colorful goodies...
View HTTP headers of a page and while browsing.
Theme Font & Size Changer lets you change the global font size and font family used for the user interface in Firefox. Design your browser with your favorite font.