Google Chrome users, be warned: a long-planned change to browser extensions is coming to fruition that could nuke your ad blocker

Google’s move to the Manifest V3 platform in Chrome (technically, a change in Chromium, so it’ll affect all web browsers that use this browser engine) is going to come into force soon, it seems, as Chrome users are being warned that this is the case.

The switch from Manifest V2 to the new V3 spin on the platform – which governs how browser extensions work – has been a long time in the works, and it promises to bring serious changes across many fronts.

As Ars Technica reports, it’s seemingly happening for real at this point, with Chrome users seeing warnings that “this extension may soon no longer be supported” with some V2 extensions (as these will need updating to V3, once the platform is fully in place on Chrome).

One type of extension that will be harder hit is the ad blocker, due to the way V3 restricts the capabilities of some extensions and how they interact with a web page. And as Bleeping Computer spotted, some Chrome users who have uBlock Origin installed have begun to see notifications warning them that this particular ad blocking extension will soon be unsupported. The pop-up warning also apparently offers advice suggesting that they “remove or replace it with similar extensions” from the Chrome Web Store.

(Image credit: Future)

A final farewell to Manifest V2

In short, Google appears to be drawing the final curtain over existing Manifest V2 extensions, although as noted, this has been a very slow process (Manifest V3 was first revealed six years ago, in fact). More recently, Google stated that V2 extensions were going to have support dropped in test versions of Chrome from June 2024, and this process now seems to be kicking up a gear (in the release version of the browser – Chrome 127 to be precise). If you head to your extensions page in Chrome, you’ll see warnings attached to any extensions built on V2, in fact.

Ars Technica further points out that Google has previously said that Chrome users may be able to manually re-enable V2-powered extensions for a “short time,” but that this option will be ditched down the line.

Google is clearly convinced of Manifest V3’s merits, stating that the new platform was crafted for better “security, privacy, performance, and trustworthiness of the extension ecosystem” – but other concerned parties aren’t nearly as enthusiastic about it.

The Electronic Frontier Foundation (EFF), a nonprofit organization focused on defending civil liberties in the digital world, isn’t convinced that Manifest V3 will deliver better security. Furthermore, Mozilla, the nonprofit best known for developing the Firefox browser, is keeping support for V2 extensions going, although it will introduce V3 support for Firefox in the spirit of maintaining cross-browser compatibility.

Others, including the developers of ad blockers themselves, are seriously unhappy with the shift to V3, and specifically the change to prevent the ability to use any remotely hosted code. This security move has the side-effect for ad blockers that they can’t (remotely) access the regularly updated filtering lists they need without going through the Chrome Web Store’s review process, as Ars Technica points out. In other words, it’ll mean this updating process – which is crucial for advert blocking – will be slowed down considerably, hampering the overall effectiveness of said extensions.

This isn’t the case according to Google’s own thoughts about ad blockers imparted via its security blog. The company insists that it “isn’t killing ad blockers,” and, in fact, it’s actually “making them safer” we’re told.

Google further argues that the switch to V3 won’t be all that disruptive, claiming earlier this year that 85% of actively maintained extensions in the Chrome Web Store already have Manifest V3 versions ready.

Clearly, that isn’t the case for uBlock Origin, though, and this ad blocker apparently won’t get a full version that’s compatible with Manifest V3 at all – instead, a ‘lite’ variant of the extension will be released as a V3 take, but it won’t have the same capabilities as the existing full-fat release.

It’s true that right now, Google probably has bigger issues on its plate such as the recent antitrust decision in the US. However, this is an important change for Chrome, which is by far the most dominant web browser – and I’m sure Google would like to keep it that way. For this reason first and foremost, Google should take great care with shifts like this one which can noticeably change the user experience.