Last updated:
59% of users voted this helpful
Add-ons are little apps that add new functionality to Thunderbird (extensions) or change its appearance (themes). This article shows you how to install an add-on to your Thunderbird.
Table of Contents
The ideal case
In an ideal world, all the add-ons you would want are officially vetted, approved, and can be found on the official website, addons.thunderbird.net.
For add-ons that fall into this category, you can simply go to the Add-ons Manager tab in Thunderbird by clicking the menu button 
followed by and click on the panel on the left to display the search box in the top-right corner. Enter the add-on's name or enough of it to limit the search results returned to a manageable number and press EnterReturn or click the magnifying glass icon.
Once you have done your first search, a new category appears in the panel on the left. You can keep refining your search until you find what you want.
Here is a search for add-ons that mention "Contacts":
Once you locate an add-on you like, click on , wait for it to be downloaded, then click on Restart now if prompted.
A slightly less ideal case (Install from a downloaded XPI file)
You may have been given an URL for the add-on, or the add-on you want isn't on the "official" page. Searching for it, as shown above, doesn't locate the add-on.
Visit the webpage in your browser, right-click the download link with your mouse, select and save the XPI file to a location on your computer that is easy to remember. As the download is temporary, it is suggested you use either your Downloads folder or your desktop.
To install a downloaded XPI file into Thunderbird, you have two options.
Download
Right-click the link and select or as described earlier.
You will be invited to download and save the file. Most browsers have a default download location. Make a note of where it downloads to, and what it's called. Some add-on files may have silly names like "latest-234.xpi", which is not very helpful when you're trying to find it later on.
Open the Add-ons Manager tab in Thunderbird. There's a button to the left of the search box. Click this and select from the subsequent menu.
You will need to navigate to where you saved the XPI file using the file picker and select it to complete the install.
Drag-and-drop
- Open the add-ons manager (click the menu button and then ).
- Drag your downloaded XPI file to the Add-ons Manager tab and drop it.
If you are using Windows, you can even skip the desktop bit. Open your browser and Thunderbird side by side, with Thunderbird's Add-ons Manager tab displayed. Drag the link directly from the browser onto Thunderbird's Add-ons Manager tab. The main advantage of this method is that you don't need to actually save a copy of the add-on to your hard disk before it is installed.
