.XPI File Extension

.XPI File Extension

File Type

Cross-platform Installer Package

Developer Mozilla
Popularity
4.1  |  677 Votes
Category Plugin Files
Format Zip

What is an XPI file?

An XPI file is a compressed installation archive used by various Mozilla applications, including Firefox, Thunderbird, and SeaMonkey. It contains software, such as a web browser plugin, extension, or theme. XPI files also include an install.js or install.rdf file, which stores the installation instructions.

More Information

Some versions of Firefox allow you to install XPI files may by simply dragging and dropping the file onto an open web browser window. The Mozilla software uses a component called XPInstall, (which includes Mozilla installer script) to install the XPI packages.

If dragging and dropping the XPI file does not work, you can install the file in Firefox following the instructions below:

  1. In Windows, select the Menu (three horizontal line) icon in the upper-right corner and click Add-ons (select Tools → Add-ons in macOS).
  2. Select Extensions, Themes, or Plugins.
  3. Click the gear icon dropdown menu and select Install Add-on From File....
  4. Navigate to and choose your XPI file and click Open.

Here are instructions for installing an XPI file in Thunderbird:

  1. In Windows, select the Menu (three horizontal lines) icon, click Add-ons, then Add-ons again (select Tools → Add-ons in macOS).
  2. Select Extensions, Themes, or Plugins.
  3. Click the gear icon dropdown menu and select Install Add-on From File....
  4. Navigate to and choose your XPI file and click Open.

Since an XPI file is Zip-compressed, you can manually extract the contents in the file by renaming the .xpi extension to .zip then extracting the contents with a Zip compression utility, such as Corel WinZip, 7-Zip, or Apple Archive Utility. You most likely will find a .JAR file, which is typically used for containing the software to install, and an install.js or install.rdf file.

Open over 400 file formats with File Viewer Plus.Free Download

Programs that open XPI files

Verified by FileInfo.com

The FileInfo.com team has independently researched the Cross-platform Installer Package file format and Mac, Windows, and Linux apps listed on this page. Our goal is 100% accuracy and we only publish information about file types that we have verified.

If you would like to suggest any additions or updates to this page, please let us know.