Google published an update on the deprecation timeline of so-called Manifest V2 extensions in the Chrome web browser. Starting this June, Chrome will inform users with classic extensions about the deprecation.

Manifests are rulesets for extensions. They define the capabilities of extensions. When Google published the initial Manifest V3 draft, it was criticized heavily for it.

This initial draft had significant impact on content blockers, privacy extensions, and many other extension types. Many called it the end of adblockers in Chrome because of that. In the years that followed, Google postponed the introduction and updated the draft several times to address some of these concerns.

Despite all the changes, Manifest V3 is still limiting certain capabilities. The developer of uBlock Origin listed some of these on GitHub. According to the information, current uBlock Origin capabilities such as dynamic filtering, certain per-site switches, or regex-based filters are not supported by Manifest V3.

The release of uBlock Origin Minus highlights this. It is a Manifest V3 extension, but limited in comparison to the Manifest V2-based uBlock Origin.

Google's Manifest V2 deprecation timeline

Google plans to show a banner to Chrome users who run Manifest V2 extensions in their browser. This starts on June 3 for development editions -- Beta, Dev, and Canary -- of the browser.

Manifest V2 extensions that have the Feature badge will lose that badge on that day.

The extensions management page in Chrome lists the soon-unsupported extensions. It provides a link to read up on the change and "find alternative" buttons next to each extension.

Then, in the months that follow, Manifest V2 extensions will be disabled automatically by Chrome. Google says that users may enable the extensions again for a short period of time. This option will be removed eventually, leaving users with no option to re-enable their extensions.

The change rolls out to development builds first, but in the coming months, will also hit Chrome Stable users.

Enterprise customers get a one year extensions. They need to set the policy ExtensionManifestV2Availability for that. Google plans to deprecate the policy in June 2025.

Tip: set chrome://flags/#extension-manifest-v2-deprecation-warning to Enabled in Chrome to see which of the installed extensions still use Manifest V2.

Closing Words

Most Chromium-based browsers will follow Google. Some may extend support for Manifest V2 extensions, but in the end, it is likely that support will be dropped.

This leaves Firefox as an alternative, as it will continue to support Manifest V2 next to Manifest V3.

It is still unclear how many extensions are affected by Google's decision. Some cannot be upgraded to Manifest V3, at least not without introducing limitations or removing features.

Extensions that are no longer maintained may also stop working, provided that they have not been updated to Manifest V3.

All in all, content blockers will no longer be as effective as they were previously in Chromium-based browsers. The majority of users may not notice the change. Content blockers continue to work, but with limitations.

Integrated content blockers continue to work. This is the case for Brave, Vivaldi, or Opera, which all include options to block ads and tracking without installation of extensions.