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.xpi

Firefox add-on

Executables & Installers

XPI packages Firefox add-ons with code and settings. Installation depends on signing, Firefox compatibility and policy. Verify authorized distribution and resolve support problems without disabling protection.

Main use
Distributing Firefox add-ons
Data type
Code-bearing installation / execution format
All sections, questions and sources

Content reviewed： · Editor：Kai

Example: a practical checking sequence

Example: for a rejected XPI, distinguish signature, Firefox version, corruption and policy. Obtain a supported authorized build rather than disabling signing checks. Review permissions before installation; renaming does not port it to Chrome.

Opening steps

Choose your environment or purpose to see its steps.

Install through Mozilla Add-ons

Verify author and listing.

  1. Check the legitimate listing and supported Firefox version.
  2. Review permissions and privacy information before adding.
  3. Check behavior and access through Add-ons Manager.
Install an authorized signed XPI

Use file installation only for trusted distribution.

  1. Verify publisher, signing and compatibility.
  2. Use Install Add-on From File in Add-ons Manager.
  3. Review permissions; request a supported build if rejected.

Menu labels and support vary by app, OS and version. Preserve the original before making changes.

Troubleshooting by symptom

  • Unsigned/corrupt warning: obtain a legitimate signed build without disabling checks.
  • Version incompatibility: ask for a supported update.
  • Organizational block: consult policy.
  • Renaming to CRX fails because formats and APIs differ.
  • Excessive permissions: evaluate necessity and decline when unsuitable.

Use browser-specific distribution

  1. Check target browser and version.
  2. Use the publisher’s official build for other browsers.
  3. Remove unused add-ons through browser management.

Renaming does not port extensions; code adaptation, signing and distribution are separate development tasks.

Signing and trustworthy distribution

Signing is part of Mozilla distribution requirements, not a complete guarantee of appropriate behavior; verify publisher and permissions too.

Source for these steps：Mozilla · Signing and distribution overview

Installation troubleshooting order

Distinguish version, signature, corruption and policy issues using official troubleshooting instead of unknown bypass instructions.

  • Retrieve the authorized build.
  • Check support and permissions.
  • Consult administrators on managed PCs.

Source for these steps：Mozilla · Unable to install add-ons

Related-format differences

Related-format differences
Format / purposeUse and preserved information
XPIFirefox add-on package.
CRXChrome extension package.
ZIPArchive-like structure does not remove signing requirements.

Handling and security

Add-ons may access browsing data; inspect provenance and permissions before installation.

Questions and answers

Does signing guarantee safety?

No; check author, purpose and permissions.

Should I disable checks for unsigned files?

No; seek legitimate signed distribution.

Can Chrome use it directly?

Obtain the official Chrome build.

Does extraction install it?

No; extraction is not installation.

What if a work PC blocks it?

Consult administrator approval and policy.

Format facts: name, steward and MIME type
Formal name
Cross-Platform Install package
Steward / specification
Mozilla
MIME type
application/x-xpinstall

Primary and official sources