Most Popular Extensions

Subscribe

DownThemAll! Featured

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

Rated 4 out of 5 stars (2,899)
288 users

Disable Add-on Compatibility Checks

Reinstates the extensions.checkCompatibility preference without respect to the current application version.

Rated 4 out of 5 stars (120)
269 users

ThunderBirthDay Requires Restart

Display birthdays from the Thunderbird addressbooks as events in Lightning.

Rated 4 out of 5 stars (97)
264 users

Flexible Identity Requires Restart

Selects an identity based on the recipients list when sending an email

Rated 4 out of 5 stars (39)
261 users

Folderpane Tools Requires Restart

Allows for customization of the folder pane. Accounts can be rearranged and the startup folder can be chosen.

Rated 3 out of 5 stars (125)
242 users

Saved Password Editor Requires Restart

Adds the ability to create and edit entries in the password manager.

Rated 5 out of 5 stars (390)
234 users

SeaMonkey Debug and QA UI Requires Restart

Provides Additional Debug and QA UI for SeaMonkey development and testing.

Rated 3 out of 5 stars (3)
214 users

Image Zoom Requires Restart

Adds zoom and rotation functionality for images...

Rated 4 out of 5 stars (355)
212 users

Theme Font & Size Changer for ThunderBird

Theme Font & Size Changer lets you change the global font size and font family used for the user interface in Firefox. Design your browser with your favorite font.

Rated 3 out of 5 stars (100)
205 users

Lightbird Requires Restart

Standalone calendar UI for Lightning

Rated 4 out of 5 stars (21)
192 users

User Agent Switcher Requires Restart

The User Agent Switcher extension adds a menu and a toolbar button to switch the user agent of a browser.

Rated 4 out of 5 stars (336)
191 users

Easiest YouTube Video Downloader

This Addon simply adds a dropdown button that lets you download YouTube Videos in various Formats. Download YouTube Videos in FLV, 3GP, MP3, MP4, 720p, 1080p in a single click.

Rated 3 out of 5 stars (47)
175 users

Session Manager

Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.

Rated 5 out of 5 stars (850)
169 users

Bluhell Firewall

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

Rated 4 out of 5 stars (498)
169 users

Speed Start

Speed Dial & Start Page with flexible layout for fast access to sites via visual bookmarks

Rated 5 out of 5 stars (82)
162 users

FireFTP Requires Restart

FireFTP is a free, secure, cross-platform FTP/SFTP client for Waterfox which provides easy and intuitive access to FTP/SFTP servers.

Check out my new project, FireSSH!

Rated 4 out of 5 stars (1,070)
161 users

Extra Format Buttons Requires Restart

Adds a font size (in pixels), strikethough, subscript and superscript buttons to Thunderbird's Compose Window.

Rated 4 out of 5 stars (19)
159 users

Quote Colors Requires Restart

Quote Colors allows you to select text and background colors of different quote levels which are applied when reading or printing mail/news messages. Additionally, you can choose between graphical and traditional plain text quoting display mode.

Rated 5 out of 5 stars (52)
150 users

Return Receipt Toolbar Button Requires Restart

Allow you to add a Return Receipt button to mail compose window toolbar.

Rated 5 out of 5 stars (21)
145 users

Cookies Exterminator

Auto delete cookies, localStorage and IndexedDB objects as soon as they become unused

Rated 5 out of 5 stars (17)
141 users