Most Popular Extensions


McAfee Security Scan Plus detection

This extension allows Adobe installers to detect McAfee Security Scan Plus software is installed on your PC.

Rated 1 out of 5 stars (13)
141,900 users

Image Zoom Requires Restart

Adds zoom and rotation functionality for images...

Rated 4 out of 5 stars (346)
141,439 users

Legacy Test Pilot (Outdated)

The legacy Test Pilot program has been replaced, and this add-on is no longer useful. If you're interested in testing new features in Firefox please join the new program at

Rated 4 out of 5 stars (71)
140,285 users

Status-4-Evar Requires Restart

Status bar widgets and progress indicators for Firefox 4+

Rated 5 out of 5 stars (556)
137,328 users

MeasureIt Requires Restart

Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.

Rated 4 out of 5 stars (358)
136,274 users

Screengrab (fix version) Requires Restart Featured

Screengrab! saves webpages as images.
0.99 released!
New features: upload to internet

Rated 5 out of 5 stars (307)
133,958 users

Nimbus Screen Capture - editable screenshots Featured

1) Screen capture web pages.
2) Selected regions.
3) Whole browser windows.
Edit screenshots and save the images to either local file or Google Drive. Annotate screenshots in a very user-friendly interface with different tools. Upload and share!

Rated 5 out of 5 stars (298)
133,746 users

New Tab Homepage

A very simple tabbed browsing extension that loads your homepage when you open a new tab. If you have multiple homepages, the first is chosen.

Rated 4 out of 5 stars (374)
133,330 users

Lucifox Requires Restart

Read EPUB e-books and browse OPDS catalogs.

Rated 4 out of 5 stars (23)
129,033 users

Text Link Requires Restart

Allows URI texts written in webpages to be loaded by double clicks.

Rated 4 out of 5 stars (298)
127,910 users

Youtube Downloader 4K - Video Downloader Requires Restart

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

Rated 4 out of 5 stars (34)
126,041 users

Grammarly for Firefox

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.

Rated 3 out of 5 stars (53)
126,025 users

ChatZilla Requires Restart Featured

A clean, easy to use and highly extensible Internet Relay Chat (IRC) client.

Rated 4 out of 5 stars (125)
125,625 users

Tab Scope Requires Restart Featured

Preview and navigate tab contents through popup.

Rated 4 out of 5 stars (476)
124,389 users

YouTube ALL HTML5 Featured

Play all videos on youtube without flash in your preferred size using only HTML5.

Rated 4 out of 5 stars (153)
124,226 users

Youtube and more – Easy Video Downloader

Download and save videos playing on a website like youtube to your hard disk

Rated 4 out of 5 stars (462)
121,491 users

DOM Inspector Requires Restart

DOM Inspector is a tool that can be used to inspect and edit the live DOM of any web document or XUL application. The DOM can be navigated using a two-paned window displaying a variety of different views on the document and all nodes within.

Rated 5 out of 5 stars (70)
121,372 users

Modify Headers Requires Restart

Add, modify and filter the HTTP request headers sent to web servers. This addon is particularly useful for Mobile web development, HTTP testing and privacy.

Rated 4 out of 5 stars (76)
121,041 users

Youtube MP3 Podcaster Requires Restart

Self contained add-on for downloading youtube videos to mp3 for easy listening on podcasting gadgets like a Zune or iPod

Rated 4 out of 5 stars (240)
120,892 users

Print Edit Requires Restart Featured

Allows editing of web page content while in Print Preview mode, prior to printing or saving as HTML or PDF. Compacts the layout and removes unwanted content such as adverts, sidebars and blank pages. Any element can be formatted, hidden or deleted.

Rated 5 out of 5 stars (309)
120,033 users