Most Popular Extensions

Subscribe

ShowIP Requires Restart

Show the IP address of the current page in the status bar. It also allows querying custom information services by IP (right click) and see location and avaiable vouchers for shopping sites. Additionally you can copy the IP address to the clipboard.

Rated 3 out of 5 stars (287)
37,012 users

Classic Toolbar Buttons

'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 (161)
36,959 users

Disable Add-on Compatibility Checks

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

Rated 4 out of 5 stars (107)
35,378 users

Diagnostics for Adblock Plus

Diagnostics tool for Adblock Plus, provides some insight into internal processes of Adblock Plus.

Not yet rated
33,490 users

Google Contacts Requires Restart

Access to Google contacts and synchronize them with Thunderbird address books.

Rated 3 out of 5 stars (316)
33,446 users

AttachmentExtractor Requires Restart

Extracts all attachments from selected messages and then can delete, detach or mark-read.

Rated 4 out of 5 stars (179)
33,431 users

SmoothWheel Requires Restart

Scrolls the page smoothly when scrolling the mouse wheel (or keyboard arrows if enabled).

Rated 5 out of 5 stars (267)
33,375 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 (75)
31,999 users

Mail Redirect Requires Restart Featured

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

Rated 4 out of 5 stars (131)
31,827 users

FireTray Requires Restart

A system tray extension for Linux and Windows, allowing to set up custom icon, hiding to tray instead of closing, display the number of unread messages in mailing applications, and other features ...

Rated 4 out of 5 stars (267)
31,425 users

新同文堂 (New Tong Wen Tang) Requires Restart

NewTongWenTang is a tool to switch display Chinese content between traditional and simplified glyphs (中文繁簡體互轉工具)

Rated 4 out of 5 stars (98)
31,277 users

Clippings Requires Restart

Save frequently-entered text for pasting later.

Rated 4 out of 5 stars (194)
30,420 users

Tiny JavaScript Debugger Requires Restart

TinyJSD is a JavaScript debugger for privileged code running Mozilla products like Firefox, Thunderbird, SeaMonkey. It serves to debug the application as well as extensions written in JavaScript.

Rated 4 out of 5 stars (7)
29,751 users

Display Mail User Agent Requires Restart

Displays icon for user agent of received mails.

Rated 4 out of 5 stars (104)
29,566 users

Folderpane Tools Requires Restart

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

Rated 4 out of 5 stars (122)
29,419 users

Stationery Requires Restart

Extension to mimic Outlook Express Stationery.
Allow you to use HTML files as templates for mail. Also allow custom template in replies or forwarded mail!

Rated 4 out of 5 stars (109)
29,418 users

Addressbooks Synchronizer Requires Restart

Synchronizes selected addressbooks with other instances of thunderbird
using ftp/webdav/imap servers

Rated 4 out of 5 stars (59)
29,024 users

Noia Fox options Requires Restart

Options manager and fixes for Noia Fox theme 3.x.x

Rated 5 out of 5 stars (15)
28,011 users

PrintingTools Requires Restart

Adds some options to print messages and addressbooks

Rated 4 out of 5 stars (24)
26,844 users

Minimize On Start and Close Requires Restart

A remake of the MinimizeToTray-extension made to fit the Windows 7 taskbar. Instead of minimize the window to the tray it minimize it to the taskbar. It can minimize on startup, when the window is closed and/or when the esc key is pressed.

Rated 4 out of 5 stars (115)
26,269 users