File Extension XPI

File type: Mozilla Installer Package XPI

About the XPI file type:

If Windows cannot find the appropriate program associated with .XPI files, then your registry may have errors. Check your Windows registry for errors (includes file association errors).

XPI is a file extension associated with the XP Installer Package, which comes along with Mozilla and Firefox. An XPI file is a compressed file which both programs can open, and is usually used to download and install software components or extensions.