Google Is Changing How Chrome Extensions Work, and Could Disable Some of Your Favorites

One of the reasons Google Chrome is such a popular browser is that it's supported by a wealth of useful third-party extensions and plug-ins, adding extra functionality and features on top of the main browser itself. Now Google is making a significant change to the way extensions work, and it could affect some key ones you've got installed.

It's all to do with the guidelines that extensions must follow to work in Chrome: Google is now retiring the old Manifest V2 spec and moving everything over to the newer Manifest V3 spec. In Google's words, V3 brings with it upgrades to the "security, privacy, performance and trustworthiness of the extension ecosystem as a whole"-and at the same time it gives Google more control over what add-ons can and can't do.

This is a common move for tech companies, and not just Google: Promising more protection for users while at the same time adding restrictions on what they can do (the Electronic Frontier Foundation doesn't think the move will improve security for users). In particular, ad blockers could be hard hit by the move to Manifest V3, because it puts more limits over the way extensions can interact with the content of websites.

AdBlock has been updated for Manifest V3. Credit: Lifehacker

There's a feature in Manifest V2 called WebRequest, which ad blockers rely on to spot adverts and stop them from appearing. This is being replaced by a new feature called DeclarativeNetRequest, which works along similar lines but is more restrictive in terms of how ad blockers can operate: Google says this means a malicious extension is less likely to cause damage, but it also means some extensions can't work in the same way.

For example, the "rules" that extensions can apply to sites is now capped at 30,000, even though ad blockers typically need ten times that number to cover all the different types of ad requests. What's more, code hosted remotely outside of an extension (so, run from the cloud) can no longer be executed, making it harder for ad blockers to maintain blocking lists and update them on the fly.

With no remotely hosted code, everything must be included in the main extension package, which is of course subject to review by Google before it appears on the Chrome Web Store-and there are some concerns that this means certain functionality will be blocked, or that ad-filtering lists might be limited. Changes to these lists are currently done multiple times a day, but will now need Google's approval each time.

What happens next

The transition to Manifest V3 has already begun, which means you might have been seeing warnings appearing on your Chrome extensions page. From a browser tab, click the three dots (top right), then choose Extensions > Manage Extensions. Those that are still on Manifest V2 will be listed as ones that "may soon no longer be supported."

Google says these extensions will be disabled in the "coming months" if they aren't updated. You can either check with the developers of your extensions to see if a Manifest V3 version is in the pipeline, or use the Find alternative links next to each of the listed add-ons to find something else in the Chrome Web Store that does a similar job.

As far as ad-blockers go, it's a pretty mixed picture. AdBlock now has a Manifest V3 version that's available to use, albeit with some of the restrictions that we've already talked about: Users are limited to fewer filter lists (you'll only be able to have 50 active ones at any one time), and those lists are going to be updated less often.

You can check which of your extensions are set to be disabled. Credit: Lifehacker

Another popular ad-blocker, uBlock Origin, won't be continuing in its current form. While there is now a uBlock Origin Lite replacement live on the Chrome Web Store, its developers say some of the filtering capabilities of the original extension can't be ported over. How that affects users will vary depending on the websites they're visiting and the type of ad-blocking they need.

This is a move that's been years in the pipeline, but the full consequences aren't clear yet. It's a good idea to do a full audit of the Chrome extensions you have installed, and see how you might be affected: Most extensions that are still actively developed should have plans to switch to Manifest V3, or at least an explanation of why they can't.

Of course, there are also plenty of alternative browsers out there these days, so you might want to consider switching to something else if you can take your favorite plug-ins and add-ons along with you. It's worth noting that Firefox, for example, is going to continue to support Manifest V2 extensions for the foreseeable future.