As of November 3rd 2025, all new Firefox extensions will be required to specify if they collect or transmit personal data in their manifest.json file using the browser_specific_settings.gecko.data_collection_permissions key. This will apply to new extensions only, and not new versions of existing extensions. Extensions that do not collect or transmit any personal data are required to specify this by setting the none required data collection permission in this property.

This information will then be displayed to the user when they start to install the extension, alongside any permissions it requests.

This information will also be displayed on the addons.mozilla.org page, if it is publicly listed, and in the Permissions and Data section of the Firefox about:addons page for that extension. If an extension supports versions of Firefox prior to 140 for Desktop, or 142 for Android, then the developer will need to continue to provide the user with a clear way to control the add-on’s data collection and transmission immediately after installation of the add-on.

Once any extension starts using these data_collection_permissions keys in a new version, it will need to continue using them for all subsequent versions. Extensions that do not have this property set correctly, and are required to use it, will be prevented from being submitted to addons.mozilla.org for signing with a message explaining why.

In the first half of 2026, Mozilla will require all extensions to adopt this framework. But don’t worry, we’ll give plenty of notice via the add-ons blog. We’re also developing some new features to ease this transition for both extension developers and users, which we will announce here.