Third-party applications (such as antivirus software, archiving software, and other tools) may load modules into Firefox. Sometimes, these applications load harmful modules that cause Firefox crashes, reduced performance, or compatibility issues. You may not notice that a malicious or unexpected module has been loaded and it may cause problems that appear to be Firefox issues.

The Firefox about:third-party page gives users information about third-party modules that have been injected into Firefox.

Accessing the about:third-party page

Type about:third-party in the address bar and press Enter. You will be taken to the Third-party module Information page. This page shows users a list of modules that have been loaded into the browser, new modules loaded and modules that are slow to load. If you see a Reload with system info button on top of the page, click on it to reload the page and see more useful information about any modules you have installed.

Application Basics

• Module information (name, version)
• Application name/publisher if provided by the third-party vendor/developer.

Module type label

• Button to copy raw json data to clipboard
• Button to show a module’s file in Windows Explorer
• Detailed table of loading events (which is collapsed by default)
• Target process (limited to browser/tab/rdd)
• Loading duration
• Background label if it was loaded in a background thread
• Status (Loaded or Blocked)

Application Notifications

• An unsigned icon (padlock with a red strike over it ) will appear next to the name of the module, if such module hasn’t been digitally signed.
• A warning triangle will appear next to the name of a module if such module has caused a crash before.