Most Popular Extensions


Adblock Plus 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 (4,894)
19,972,040 users

Lightning Requires Restart Featured

Organize your schedule and life's important events in a calendar that's fully integrated with your Thunderbird email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars.

Rated 3 out of 5 stars (1,922)
5,869,681 users

uBlock Origin

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

Rated 5 out of 5 stars (693)
1,705,962 users

FlashGot Mass Downloader Requires Restart

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 (535)
783,010 users

Element Hiding Helper for Adblock Plus

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 (452)
584,924 users

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.

Rated 4 out of 5 stars (836)
449,292 users

ImportExportTools Requires Restart

Adds some tools to import and export folders and messages

Rated 4 out of 5 stars (150)
376,190 users

S3.Google Translator Requires Restart

S3.Google Translator adds the power of Google Translate’s automatic translations to your browser!
It supports translation of selected text, entered phrase or whole webpage between any of 80+ languages.

New Feature: Language learning!

Rated 5 out of 5 stars (382)
373,453 users

Provider for Google Calendar Requires Restart

Allows bidirectional access to Google Calendar

Rated 4 out of 5 stars (1,008)
330,689 users

Full Web Page Screenshots (♥♥♥♥♥) Requires Restart

FireShot makes full web page screenshots. Demo:

Screenshots can be quickly captured and:

― Saved as Image or PDF
― Sent to clipboard
― Printed
― Annotated *
― Uploaded *
― E-Mailed *

* OS Windows only

Rated 5 out of 5 stars (465)
275,092 users

Personas Plus

Personas (now known as lightweight themes) are free, easy-to-install "skins" for Firefox. Personas Plus extends that built-in functionality to give you even more control and easier access to new, popular, and your own favorite themes.

Rated 3 out of 5 stars (933)
273,341 users

FoxyProxy Standard Requires Restart

FoxyProxy is an advanced proxy management tool that completely replaces Firefox's limited proxying capabilities. For a simpler tool and less advanced configuration options, please use FoxyProxy Basic.

Rated 4 out of 5 stars (365)
264,765 users

HTTPS Everywhere Requires Restart

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 (120)
243,300 users

Download Status Bar

If you are the kind of person who likes to have total control over every aspect of your downloads, "Download Status Bar" is the add-on you are looking for.

Rated 5 out of 5 stars (331)
230,223 users

MinimizeToTray revived Requires Restart

Minimizes windows into the system tray.

Rated 5 out of 5 stars (327)
215,565 users

Password Exporter

This extension allows you to export your saved passwords and disabled login hosts using XML or CSV files that can be imported later.

Rated 4 out of 5 stars (359)
201,940 users

LookOut Requires Restart

LookOut is a plugin which allows Thunderbird to interface with Microsoft's mail tools by decoding metadata and attachments encapsulated/embedded in a TNEF encoded attachment (aka winmail.dat).

Rated 4 out of 5 stars (150)
198,729 users

SQLite Manager Requires Restart

Manage any SQLite database on your computer.

Rated 4 out of 5 stars (58)
189,820 users

Quick Locale Switcher Requires Restart

Allows you to quickly switch to a different language (User Interface, Spell Checker Dictionary and Website content) in your Mozilla application.

Rated 3 out of 5 stars (88)
170,149 users

Enigmail Requires Restart Featured

OpenPGP message encryption and authentication for Thunderbird and SeaMonkey.

Rated 4 out of 5 stars (195)
158,961 users