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 Compatible with Firefox 57+ Featured
Finally, an efficient blocker. Easy on CPU and memory.
Join WebEx meetings using Firefox ™
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, an award-winning password manager, saves your passwords and gives you secure access from every computer and mobile device.
The most popular ad blocker for Chrome and Safari, now available for Firefox! Block all advertisements on all web pages, even Facebook, Youtube, and Hulu. Browse faster, too! Most ads aren't even downloaded at all, saving you time and bandwidth.
Grammarly will help you communicate more effectively. As you type, Grammarly flags mistakes and helps you make sure your messages, documents, and social media posts are clear, mistake-free, and impactful.
Free and improved ad blocker. Completely remove ALL ads. No "acceptable" ads or whitelisted advertisers, block tracking, block malware!
This is an official Amazon extension for Firefox. Amazon Assistant helps you make better shopping decisions by showing product comparisons at thousands of retail sites. By installing you agree to the Conditions of Use at amazon.com/gp/BIT/TOU.
Protects your privacy by blocking spying ads and invisible trackers.
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
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.
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.
YouTube High Definition is a powerful tool that will let you automatically play all YouTube videos in HD (High Definition), turn off annotations, change video player size, auto stop videos, auto mute videos, control embedded videos and much more.
Instantly know which websites to trust! WOT protects you while you browse, warning you against dangerous sites that host malware, phishing, and more.
Keep your Firefox bookmarks on Windows up to date with your Safari bookmarks on iPhone, iPad, and Mac with the iCloud Bookmarks extension for Firefox.
Removes all annoying Ads from YouTube
WORKS WITH NEW YOUTUBE LAYOUT, "Best Youtube Video Downloader", Only one with 1080p Full-HD and 256kbps MP3 Direct Links. A clean, fast and simple addon for superfast and easy downloads in FLV, 3GP, MP3, MP4, 720p, 1080p qualities on Youtube pages.