Manifest V3: Thousands of Chrome extensions become unusable

Back in 2018, Google announced its intention to change the interfaces from the old standard, Manifest V2, to a new one: Manifest V3. After years of preparation, the manufacturer is now getting serious. Users of V2 extensions will see a warning in the browser informing them that they will soon no longer work. If you want to install a V2 extension from the Chrome Store, Google will present you with a similar warning and V3-compatible alternatives to the extension you are looking for.

Starting with the current version 127, Google intends to "gradually" switch off V2 support in its browser. According to Google, this will start with the non-pre-release versions of Chrome (Der, Canary and Beta). Google is granting companies that specify the availability of V2 extensions with the ExtensionManifestV2Availability group policy a grace period until June 2025.

According to surveys by chrome-stats.com, there are still well over 50,000 extensions that still use the old standard. Due to the changeover, these will no longer work after the changeover.

The changeover has always been controversial in the scene. Google cites the more modern architecture, higher security and better performance of the new standard as arguments in favor of V3. Consumer advocates from the Electronic Frontier Foundation (EFF), on the other hand, described V3 as "fraudulent and threatening".

Ad blockers slowed down

Ad blockers are particularly hard hit by the changes. According to Raymond Hill, the programmer of the popular ad blocker uBlock Origin, the new standards mean that extensions can no longer block ads as reliably as before.

In future, Hill will only offer the slimmed-down version uBlock Origin Lite (uBOL) for Chrome browsers and recommends that users of his extension switch to Firefox because uBlock Origin works best there (Mozilla continues to support V2 alongside V3 for its Firefox browser)

Other manufacturers have provided versions of their ad blockers for Manifest V3, such as AdBlock Plus and AdGuard. While the manufacturer of AdBlock Plus does not go into detail about the effectiveness of its new version, AdGuard has written a detailed blog post about the effects of Manifest V3.

In response to the question "Is it true that ad blockers will work much worse in the future?" it says: "No, that's not true. Although ad blockers will lose a small part of their functionality, they will still be able to provide almost the same filtering quality as with Manifest V2."

And other browsers?

In this context, the question arises as to how the changes will affect other browsers - after all, Edge, Vivaldi and Brave, among others, are based on the same code base as Chrome. Microsoft has announced that it will fully support the switch to V3 and that Edge will one day no longer support V2 extensions. However, the timeline is silent on when the switch will take place.

Vivaldi intends to support V2 extensions until June 2025. However, the company itself does not yet know what impact V3 will have in detail. In a blog post, Vivaldi developer Julien Picalausa cannot definitively rule out the possibility that Google's changes will not also affect the Vivaldi ad blocker.

And Brave's announcements also contain some cautious wording: They want to provide "limited" support for V2 even when it is finally removed from the Chrome (-ium) code, i.e. in June 2025, and explicitly plan to support the ad blockers AdGuard AdBlocker, NoScript, uBlock Origin, and uMatrix in their V2 versions "as best they can".

It looks as though users and developers of add-ons and browsers could be in for some frustration in the coming weeks.

(jo)