Most Popular Extensions


Adblock Plus No Restart Featured

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 (4,989)
21,690,319 users

Video DownloadHelper No Restart

The easy way to download and convert Web videos from hundreds of YouTube-like sites.

Rated 4 out of 5 stars (5,857)
4,750,548 users

NoScript Security Suite Featured

The best security you can get in a web browser!
Allow active content to run only from sites you trust, and protect yourself against XSS and Clickjacking attacks.

Rated 5 out of 5 stars (1,509)
2,342,114 users

Firebug No Restart

Firebug integrates with Firefox to put a wealth of development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page...

Rated 5 out of 5 stars (1,799)
2,160,934 users

Easy Screenshot

Capture a screenshot of the whole webpage, and save in your desktop in default.

Rated 4 out of 5 stars (70)
2,013,625 users

Ghostery No Restart Featured

Enjoy a faster, safer and cleaner browsing experience.

Rated 5 out of 5 stars (1,237)
1,543,179 users

DownThemAll! Featured

The first and only download manager/accelerator built inside Firefox!

Rated 5 out of 5 stars (1,626)
1,351,861 users

Greasemonkey Featured

Customize the way a web page displays or behaves, by using small bits of JavaScript.

Rated 4 out of 5 stars (964)
1,264,120 users

Adblock Plus Pop-up Addon Featured

Adblock Plus Pop-up Addon extends the blocking functionality of Adblock Plus to those annoying pop-up windows that open on mouse clicks and other user actions.

Rated 5 out of 5 stars (182)
1,243,679 users

Flash Video Downloader - YouTube HD Download [4K]

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.

Rated 4 out of 5 stars (546)
1,115,801 users

Web of Trust, WOT: Website Reputation Ratings Featured

Find out which websites you can trust. WOT adds intuitive traffic light-style icons next to search results and URLs so you can decide whether to visit a site:
• Green – The site is trusted
• Yellow – Be cautious
• Red – Online threats detected

Rated 3 out of 5 stars (1,649)
1,056,063 users

Download YouTube Videos as MP4 No Restart Featured

An extension that adds direct links to download YouTube videos as MP4 and FLV. It has a simple interface and it downloads videos directly from YouTube. The extension integrates with YouTube's interface and adds a download button below the player.

Rated 4 out of 5 stars (371)
1,008,943 users

FlashGot Mass Downloader Featured

Download all the links, movies and audio clips of a page at the maximum speed with a single click, using the most popular, lightweight and reliable external download managers.

Rated 5 out of 5 stars (504)
930,921 users

Tab Mix Plus Featured

Tab Mix Plus enhances Firefox's tab browsing capabilities. It includes such features as duplicating tabs, controlling tab focus, tab clicking options, undo closed tabs and windows, plus much more. It also includes a full-featured session manager.

Rated 4 out of 5 stars (2,549)
895,031 users

Google Translator for Firefox Featured

With this addon you can translate any text to your own language with one click or hot-key. You can either translate the selected text, this way the translated text will overwrite the original selected text, or you can translate the full page too.

Rated 4 out of 5 stars (312)
812,308 users

Test Pilot

Help us make Firefox better by joining our structured user studies! No need to download this add-on if you are running Firefox 4 beta, - you are already a part of the team!

Rated 4 out of 5 stars (71)
760,961 users

Element Hiding Helper for Adblock Plus No Restart

Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.

Rated 5 out of 5 stars (451)
748,076 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 (1,249)
745,136 users


Never be annoyed by a Flash animation again! Blocks Flash so it won't get in your way, but if you want to see it, just click on...

Rated 4 out of 5 stars (1,176)
707,279 users

1-Click YouTube Video Download

The simplest YouTube Video Downloader for all YouTube Flash sites, period.

Rated 4 out of 5 stars (500)
699,609 users