ImportExportTools Requires Restart

Adds some tools to import and export folders and messages

Rated 4 out of 5 stars (175)
461,149 users

Provider for Google Calendar Requires Restart

Allows bidirectional access to Google Calendar

Rated 4 out of 5 stars (965)
336,908 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 (467)
255,150 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 (435)
130,171 users

MinimizeToTray revived Requires Restart

Minimizes windows into the system tray.

Rated 4 out of 5 stars (360)
120,229 users

SQLite Manager Requires Restart

Manage any SQLite database on your computer.

Rated 4 out of 5 stars (283)
115,760 users

Quicktext Requires Restart

Quicktext is an extension for Thunderbird that lets you create templates that can be easily inserted into your own emails.

Rated 4 out of 5 stars (306)
89,797 users


UnMHT allows you to view MHT (MHTML) web archive format files, and save complete web pages, including text and graphics, into a single MHT file in Firefox/SeaMonkey.

Rated 4 out of 5 stars (289)
70,931 users

Add-ons Manager Context Menu Requires Restart

Add more items to Add-ons Manager context menu.

Rated 5 out of 5 stars (46)
67,830 users

JavaScript Debugger Requires Restart

As of Firefox 33, Venkman *no longer works*, as the APIs which it needs have been removed.

Venkman is the code name for Mozilla's JavaScript Debugger. Venkman aimed to provide a powerful JavaScript debugging environment for Mozilla based browsers.

Rated 4 out of 5 stars (50)
64,877 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 (78)
61,217 users

Google Calendar Tab Requires Restart

Adds the Google Calendar web interface as a new tab directly into Thunderbird. Creating and viewing events works just as it would in a browser like Firefox

Rated 4 out of 5 stars (84)
44,826 users

Mail Redirect Requires Restart Featured

Allow to redirect (a.k.a. "remail") mail messages to other recipients.

Rated 4 out of 5 stars (128)
37,958 users

Display Quota Requires Restart

This extension will display the current status of your IMAP quota in thunderbird's statusbar and will warn you when you reach a configurable limit...

Rated 4 out of 5 stars (30)
35,849 users

PrintingTools Requires Restart

Adds some options to print messages and addressbooks

Rated 5 out of 5 stars (25)
34,883 users

GPO support For Firefox and Thunderbird

For work with new versions, use autoconfiguration module https://mozillagpo.sourceforge.io/
Firefox and Thunderbird extension to manage user preferences and user profile CA certificates using group policy

Rated 4 out of 5 stars (12)
30,883 users

Classic Toolbar Buttons [Fx45-56][Tb24-58]

'Classic Toolbar Buttons' add-on restores old toolbar button ui (known from Fx 4-7s small view, Fx 4-12s large view & Tb 5-14) for current Firefox, Thunderbird and Seamonkey versions.

Beta builds on versions page!

Rated 5 out of 5 stars (144)
24,064 users

Copy Plain Text 2 Requires Restart

Copies text without formatting

Rated 5 out of 5 stars (94)
22,768 users

ProfileSwitcher Requires Restart

It adds some options to launch easily other profiles and the Profile Manager.

Rated 4 out of 5 stars (110)
21,820 users

Font Finder Requires Restart

FontFinder is created for designers, developers and typographers. It allows a user to analyze the font information of any element on a page, copy any piece(s) of that information to the clipboard, and perform inline replacements to test new layouts.

Rated 4 out of 5 stars (78)
20,339 users