Most Popular Extensions

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Send Later Requires Restart

True "Send Later" functionality to schedule the time for sending an email.

Rated 5 out of 5 stars (77)
64,976 users

Forecastfox (fix version) Requires Restart

Get international weather forecasts from AccuWeather.com and display them in any toolbar or statusbar with this highly customizable and unobtrusive extension.

Now Available for: Firefox, Thunderbird and SeaMonkey!

Rated 5 out of 5 stars (213)
64,537 users

Custom Buttons Requires Restart

Gives a possibility to create custom toolbarbuttons...

Rated 4 out of 5 stars (111)
62,330 users

Thunderbird Conversations

This addon provides a conversation view for Thunderbird, grouping messages together and allowing you to reply "inline" thus providing a more efficient workflow.

The latest version is compatible with Thunderbird 38+ only (see below for details).

Rated 4 out of 5 stars (421)
62,285 users

FoxClocks

FoxClocks shows times around the world - or just your local time - at the bottom of your browser. It deals with daylight saving time so you don't have to.

Rated 4 out of 5 stars (326)
62,202 users

KeeFox Requires Restart

Simple and secure password management. Login automatically, never forget another password, stay in control of your passwords and improve their security. Powered by the world-renowned KeePass Password Safe.

Rated 5 out of 5 stars (1,201)
61,316 users

Exif Viewer Requires Restart

Displays the Exif and IPTC data in local and remote JPEG images.

Rated 4 out of 5 stars (85)
60,424 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 (83)
58,758 users

Google Docs Viewer (PDF, DOCX, PPTX, XLSX, etc...) Requires Restart

View publicly-accessible PDF, DOCX, PPTX, XLSX, among other files online with Google Docs by only 2 clicks. Click as usual for your default viewer. Support bookmarked URLs. Security and your explicit viewing intention are always honored.

Rated 4 out of 5 stars (61)
57,228 users

Mail Merge Requires Restart Featured

Mass Mail and Personal Mail

Rated 5 out of 5 stars (143)
56,832 users

ProfileSwitcher Requires Restart

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

Rated 4 out of 5 stars (88)
51,768 users

Remove Duplicate Messages Requires Restart

If you have duplicate messages (e.g. from merging folders or downloading messages several times) you can use this tool to find and remove them from the selected folder and its subfolder by rightclicking on a folder and choosing "Remove duplicates..."

Rated 4 out of 5 stars (130)
47,677 users

AutoProxy Requires Restart

Are you concerned about your privacy? Or, are you blocked from some websites by a firewall? And, are you arming yourself with a proxy? In that case, AutoProxy is designed for you! A tool to help you use your proxy automatically & efficiently.

Rated 4 out of 5 stars (417)
46,669 users

Confirm-Address Requires Restart

Confirm E-mail address before sending mail

Rated 4 out of 5 stars (32)
46,489 users

rikaichan Requires Restart

Japanese to English/German/French/Russian dictionary. Just hover the mouse on top of a word, and a popup appears. Automatically de-inflects verbs and adjectives. Detailed kanji view...

Rated 5 out of 5 stars (92)
45,571 users

Copy Plain Text 2 Requires Restart

Copies text without formatting

Rated 5 out of 5 stars (67)
44,613 users

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 (286)
43,695 users

Clean Links

Converts obfuscated or nested links to genuine clean links.

Eg: http://somesite.com/?to=www.example.comhttp://www.example.com/

Rated 5 out of 5 stars (111)
43,178 users

Rikaichan Japanese-English Dictionary File Requires Restart

This is a dictionary file add-on for the Rikaichan extension.

Rated 5 out of 5 stars (6)
39,902 users

Google Contacts Requires Restart

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

Rated 3 out of 5 stars (316)
39,029 users