How to open a .XPI file online
No extra software to download or install.
Pick your .XPI file
Drag it in or click to choose it. We read its contents list first, so it opens right away without unpacking everything.
Browse what's inside
See every file with its size, how much it's compressed and its date, and search by name across all the folders.
Preview or download
Click a file to preview text or images, or save just that one. Need everything? Download it all as a single ZIP.
About .XPI files
What a .XPI file is, and what's inside it.
An XPI file is a Firefox or Thunderbird add-on package, a ZIP archive containing a browser extension or theme. Install it by dragging it onto the Add-ons Manager (about:addons) in Firefox or Thunderbird. Since 2016, release Firefox only accepts Mozilla-signed XPIs; unsigned ones are blocked unless you use Firefox Developer Edition, Nightly, or about:debugging.
Programs that open .XPI files
| Full name | Cross-Platform Installer (Mozilla add-on package) |
|---|---|
| Developer | Mozilla |
| First released | 1990s (Mozilla/Netscape XPInstall); modern WebExtension XPIs since Firefox 57 (2017) |
| Category | Archives |
| MIME type | application/x-xpinstall |
| Signature | 50 4B 03 04 "PK" - standard ZIP local file header |
Related viewers
Found something inside the archive? Open it here.
Do I have to unpack the whole .XPI file?
No. The viewer reads its table of contents first and only unpacks a file when you click it. That works even with multi-gigabyte archives, because we read just the bytes we need.
Can I open password-protected archives?
Yes, for ZIP (ZipCrypto and AES) and 7Z. You'll be asked for the password,. We can't recover forgotten passwords.
Is my .XPI file uploaded anywhere?
No. The code that unpacks the file is downloaded once and then reused.
Why does a .docx or .apk open as an archive?
Because they are ZIP archives under the hood. Office documents, Android apps, Java programs and EPUB books all use ZIP as their container.
What about split archives (.001, .z01, .part1.rar)?
Multi-part archives need all their parts. Today you can open the first part to see the file list; joining parts is on our roadmap.
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