XPI File Type

- The quick facts

What are XPI files and how to open them

Are you having problems opening an XPI file or just wondering what they contain? We explain what these files are used for and show you software that we know can open or otherwise handle your files.

What is an XPI file?

An .XPI file is a Mozilla Firefox browser extension file.

XPI files are used and created by various Mozilla applications, including the Thunderbird email application and the Firefox Web browser. These .xpi files are very similar to zip files. When they are opened, the files "decompress" and install a browser extension into the Mozilla browser or Thunderbird application. An extension extends the functionality of the program without modifying the program itself. In Firefox, it could, e.g., change the New Tab page, and in Thunderbird, it could add integration into a custom calendar or email system.

To install an XPI file, a user can simply drag and drop the file into the interface of the application the file is associated with.

How to open XPI files

We have identified one XPI opener that is compatible with this specific type of XPI file.

Programs that open Mozilla Firefox browser extension files


Last updated: August 13, 2021

Suggest another file format using extension XPI

While we know of one file format using the .XPI file extension, there may be more. It is widespread that different programs use files with the same file extension for very different types of data. Please let us know if you are aware of a different kind of .XPI file.