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).
Lightning Requires Restart
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.
Finally, an efficient blocker. Easy on CPU and memory.
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.
Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.
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.
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.
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!
ImportExportTools Requires Restart
Adds some tools to import and export folders and messages
Provider for Google Calendar Requires Restart
Allows bidirectional access to Google Calendar
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.
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.
Full Web Page Screenshots (♥♥♥♥♥) Requires Restart
FireShot makes full web page screenshots. Demo: http://bit.ly/RlBQMV
Screenshots can be quickly captured and:
― Saved as Image or PDF
― Sent to clipboard
― Annotated *
― Uploaded *
― E-Mailed *
* OS Windows only
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.
This extension allows you to export your saved passwords and disabled login hosts using XML or CSV files that can be imported later.
MinimizeToTray revived Requires Restart
Minimizes windows into the system tray.
SQLite Manager Requires Restart
Manage any SQLite database on your computer.
Enigmail Requires Restart Featured
OpenPGP message encryption and authentication for Thunderbird and SeaMonkey.
Add-ons Manager Context Menu Requires Restart
Add more items to Add-ons Manager context menu.