Most Popular Extensions
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).
uBlock Origin Featured
Finally, an efficient blocker. Easy on CPU and memory.
Flash Video Downloader helps you download any video (flv, mp4, HD) from YouTube, Facebook, Break, Metacafe and more in one click. You can download mp3, music (iPod), avi and more. Download Flash games. Download Helper. 4K download.
LastPass Password Manager Requires Restart Featured
LastPass, an award-winning password manager, saves your passwords and gives you secure access from every computer and mobile device.
Capture the whole page or any portion, annotate it with rectangles, circles, arrows, lines and text, blur sensitive info, one-click upload to share. And more!
Stylish Requires Restart Featured
Restyle the web with Stylish, a user styles manager. Stylish lets you easily install themes and skins for Google, Facebook, YouTube, Tumblr, and many, many other sites. You can even customize Firefox and other programs themselves.
Free and improved ad blocker. Completely remove ALL ads. No "acceptable" ads or whitelisted advertisers, block tracking, block malware!
HTTPS Everywhere Requires Restart
Encrypt the web! HTTPS Everywhere is a Firefox extension to protect your communications by enabling HTTPS encryption automatically on sites that are known to support it, even when you type URLs or follow links that omit the https: prefix.
AdBlocker for YouTube™ removes all annoying Ads from YouTube
Join WebEx meetings using Firefox ™
Use the Evernote Web Clipper to save things you see on the web into your Evernote account.
Make the web faster, more private, and more secure.
Unmatched adblock extension against advertising and pop-ups. Blocks ads on Facebook, Youtube and all other websites.
Grammarly’s free spelling and grammar checker ensures that everything you type is easy to read, effective, and mistake-free. As you type, Grammarly underlines spelling mistakes and grammatical errors and helps you fix them on the fly.
Fix the web. 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...
Hoxx VPN Proxy service to unblock blocked websites, hide your location and encrypt your connection. Completely free.
NOTE: Users should be aware that this add-on represents an older fork. The original developer of uBlock is continuing to actively develop the newer fork uBlock Origin.