LanguageXPI
Firefox browser extension
File type: Plugin, addon file
Files with xpi extension can be commonly encountered as various Firefox plugins or add-on files. Add-ons enhance current features of the browser or add completely new functions or mini programs to the program (such as weather forecast, dictionary, password storage etc.).
What is xpi file?
File type category:
Plugin, addon file
Date updated: June 27, 2025
File extension xpi is associated with Firefox or Mozilla web browsers and used for its plugins and add-ons.
The XPI archive contains: installation settings (.rdf file extension), Manifest file (.manifest file extension), graphics files (.png, .jpg, .gif), and other data stored in .css, .js files. This is basically a ZIP file that, when opened by the Firefox browser utility, installs a browser extension. This extension applies to both Mozilla and Firefox browsers.
Other web browsers based on Firefox Gecko core, such as Seamonkey, use extensions in .xpi containers. However not all Firefox extensions are compatible with other Gecko based browsers.
MIME type used for xpi firefox plugins: application/x-xpinstall
What are Firefox extensions or Firefox Add-ons?
Firefox add-ons are small pieces of software that can add new features or tiny tweaks to customize your Firefox browser. They can add new search engines or dictionaries in other languages, change the whole look of Firefox with a new theme, or much much more. Take a look around and see what add-ons can do for you.
See related links to open Firefox addons website.
How to open xpi file?
The XPI Firefox browser extension file is the native format, that is used by Mozilla Firefox to installation of browser extensions.
The XPI Firefox browser extension file is ZIP archive with renamed file extension to XPI. You can rename XPI file extension to ZIP and file can be opened in compression utilities, that can open ZIP archive, such as WinRAR, WinZip, PeaZip, 7-zip and etc.
How to convert xpi file?
There is no way how to convert the XPI Firefox browser extension file in to other file format.
Suggested software to open xpi file:
Associated software actions with the xpi file
Software apps that import xpi files:
Firefox (Microsoft Windows)
SeaMonkey (Microsoft Windows)
Mozilla Thunderbird (Microsoft Windows)
Firefox for Mac (Apple macOS / Mac OS X)
Mozilla Thunderbird for Mac (Apple macOS / Mac OS X)
Seamonkey for Mac (Apple macOS / Mac OS X)
Firefox for Linux (Linux/Unix)
Seamonkey for Linux (Linux/Unix)
Mozilla Thunderbird for Linux (Linux/Unix)