Most Popular Extensions


Adblock Plus No Restart

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).

Rated 5 out of 5 stars (4,974)
21,738,930 users

Ghostery No Restart Featured

Protect your privacy. See who's tracking your web browsing and block them with Ghostery.

Rated 5 out of 5 stars (1,204)
1,530,899 users

Flash Video Downloader - YouTube HD Download [4K]

Flash Video Downloader helps you to download any video (flv, mp4, HD) from YouTube-like, Facebook, Break, Metacafe and more in one click. You can download mp3, music (iPod), avi and more. Download Flash games. Download Helper. 4K download

Rated 4 out of 5 stars (537)
1,165,102 users

LastPass Password Manager Featured

LastPass, an award-winning password manager, saves your passwords and gives you secure access from every computer and mobile device.

Rated 4 out of 5 stars (1,237)
777,760 users

Adblock Edge No Restart

Adblock Edge is a fork of the Adblock Plus version 2.1.2 extension for blocking advertisements on the web, without sponsored ads whitelist.

**This addon has been discontinued**

Rated 5 out of 5 stars (292)
738,184 users

Stylish Featured

Restyle the web with Stylish, a user styles manager. Stylish lets you easily install themes and skins for Google, Facebook, YouTube, Orkut, and many, many other sites. You can even customize Firefox and other programs themselves.

Rated 4 out of 5 stars (752)
693,308 users

uBlock Origin No Restart Featured

Finally, an efficient blocker. Easy on CPU and memory.

Rated 5 out of 5 stars (229)
375,798 users

µBlock No Restart

Finally, an efficient blocker. Easy on CPU and memory.

Rated 4 out of 5 stars (208)
227,235 users helper all-in-1 / youtube downloader No Restart helper will enable you to download files from,,,,,, and more than 40 other just in one click.

Rated 4 out of 5 stars (198)
189,033 users

Self-Destructing Cookies No Restart

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.

Rated 4 out of 5 stars (430)
181,792 users

AdBlock for YouTube™ No Restart

AdBlock for YouTube™ removes all annoying Ads from YouTube

Rated 4 out of 5 stars (10)
166,986 users

Youtube Downloader 4K - Video Downloader

Download from YouTube 4K videos and thousands other video websites.

Rated 3 out of 5 stars (17)
166,117 users

Bluhell Firewall No Restart Featured

Get a faster browsing experience by blocking nasty web resources using Bluhell Firewall, the lightweight Ad-Blocker and Tracking/Privacy Protector.

Rated 5 out of 5 stars (239)
141,434 users

PDF Viewer No Restart

PDF.js brings Portable Document Format (PDF) reading capabilities to your browser using web standard technologies.

Please report issues to:

Rated 4 out of 5 stars (266)
121,939 users

Video WithOut Flash No Restart

Watch videos without flash

Rated 4 out of 5 stars (54)
88,616 users

UnMHT No Restart

UnMHT allows you to view MHT (MHTML) web archive format files, and save complete web pages, including text and graphics, into a single MHT file in Firefox/SeaMonkey.

Rated 5 out of 5 stars (217)
88,177 users

Remote XUL Manager No Restart

Manages the Remote XUL whitelist to allow websites and local files to load XUL content. For versions compatible with Firefox 41 and lower, see All Versions page below.

Rated 5 out of 5 stars (35)
80,398 users

YouTube Center No Restart

YouTube Center contains all kind of different useful functions which makes your visit on YouTube much more entertaining.

Rated 3 out of 5 stars (282)
73,680 users

Simple YouTube to MP3/MP4 Converter and Downloader No Restart

Download youtube videos as mp3/mp4/ogg/webm fast and easy! Adding mirrors everyday to decrease any downtime! We monitor comments and work to fix any problems as soon as possible!

Rated 5 out of 5 stars (14)
59,598 users

HTTPS Everywhere

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.

Rated 4 out of 5 stars (31)
59,276 users