What Are XPI Files and How to Open One?

Updated June 2024: Stop getting error messages and slow down your system with our optimization tool. Get it now at this link
  1. Download and install the repair tool here.
  2. Let it scan your computer.
  3. The tool will then repair your computer.

The cross-platform installer (XPI) is a ZIP file used to install packages with XPInstall technology. XPI modules (called “bundles”) are used to install a variety of software, including plug-ins, extensions, themes and Thunderbird dictionaries.

An XPI contains both an installation guide (install.js or install.rdf) and the software to be installed, which itself is often packaged as a JAR file. When downloaded or placed in an extension manager, XPInstall automatically interacts with the installation instructions contained in the XPI and installs the included software.

XPI archives only support files that are stored uncompressed or compressed using the “Deflate” method.

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 contain an install.js or install.rdf file, which contains installation instructions.

Some versions of Firefox allow you to install XPI files by simply dragging and dropping them onto an open web browser window. Mozilla software uses a component called XPInstall (which contains the Mozilla installation script) to install XPI packages.

How do I open an XPI file?

To open an XPI file, you need appropriate software such as the Mozilla/Firefox browser from Mozilla. Without the appropriate software, you will receive a Windows message “How do you want to open this file? (Windows 10) or “Windows cannot open this file” (Windows 7) or a similar message for Mac/iPhone/Android. If you cannot open your XPI file properly, try opening the file by right-clicking the mouse or pressing and holding down the key. Then click on “Open with” and select an application.

June 2024 Update:

You can now prevent PC problems by using this tool, such as protecting you against file loss and malware. Additionally, it is a great way to optimize your computer for maximum performance. The program fixes common errors that might occur on Windows systems with ease - no need for hours of troubleshooting when you have the perfect solution at your fingertips:

  • Step 1 : Download PC Repair & Optimizer Tool (Windows 10, 8, 7, XP, Vista – Microsoft Gold Certified).
  • Step 2 : Click “Start Scan” to find Windows registry issues that could be causing PC problems.
  • Step 3 : Click “Repair All” to fix all issues.

Download Now

To convert an XPI file

There are file types similar to XPI that are used by other Web browsers to add features and capabilities to a browser, but they cannot be easily converted to and from other formats for use in another browser.

For example, while files such as CRX (Chrome and Opera), SAFARIEXTZ (Safari) and EXE (Internet Explorer) can all be used as add-ons for their respective browsers, none of them can be used in Firefox, and Mozilla’s XPI file type cannot be used in any of these other browsers.

However, there is an online tool called Add-on Converter for SeaMonkey that attempts to convert an XPI file compatible with Firefox or Thunderbird to an XPI file that works with SeaMonkey.

Creating the .xpi file

You can use any method to create the .zip file which is renamed to .xpi. Note the requirement that the only supported compression method is “deflate”, but files can also be added to the archive uncompressed. Your top-level files (for example, what you got from manifest.json (WebExtensions), or anything else: chrome.manifest and install.rdf) must be in the root directory of the archive, not in a subdirectory.


Expert Tip: This repair tool scans the repositories and replaces corrupt or missing files if none of these methods have worked. It works well in most cases where the problem is due to system corruption. This tool will also optimize your system to maximize performance. It can be downloaded by Clicking Here

Scroll to Top