Google has been working for some time on a way to block old browser extensions in Google Chrome. This goes hand in hand with the switch from Manifest V2 to Manifest V3, a newer and presumably more secure architecture for the popular browser.
As early as March 2025, this rendered some extensions—including popular ad blockers such as uBlock Origin—suddenly unusable, even though it was still possible to access them with a workaround. By the end of June, however, even that will no longer work. A future release of Chrome will block all add-ons still based on Manifest V2.
The decisive factor here is the “ExtensionManifestV2Disabled” flag in Google Chrome’s code, reports PiunikaWeb. It’s not entirely clear whether this will be permanently disabled in Chrome 150 or 151, as there are differing analyses on this point. In Chrome 150, it still seems to be possible to enable the flag, at least to some extent.
Here’s what we know for sure: once the change goes live, there’s no going back. It will be significantly more difficult to use ad blockers like uBlock Origin. Doing so would require using developer settings and making changes that would make the browser less stable.
Why is this happening?
The blocking of ad blockers is not a direct move by Google but rather a side effect of the planned switch to Manifest V3. (At least, that’s the official stance of the company.) This new architecture is intended to make the browser more secure, faster, and prevent rogue browser extensions from interfering deeply with a user’s system.
Given that there have been repeated instances of extensions posing a serious threat, it’s understandable that Google wants to prevent that from happening. The fact that it can also hamper ad blockers with the same move is just a bonus that Google is unlikely to be too upset about.
Developers have the option to adapt existing extensions to Manifest V3 and modify them so that they still work. However, there’s no guarantee that the same functionality will be available.
What can you do about it?
If you’re still relying on uBlock Origin, it’ll soon be time to switch over to something else. We’ve highlighted ad blockers that will still work with Chrome, including uBlock Origin Lite (the successor to uBlock Origin with fewer features but fully compatible with Manifest V3).
