Google Chrome automatically disables uBlock Origin

On 4 March 2025, Google Chrome automatically disabled uBlock Origin, the most popular content blocker to date, for all users as part of shift to the Manifest V3 version of Chrome.

Background

µBlock, first published on 23 June 2014, was forked into uBlock Origin and released on 23 June 2018. It is a wide-spectrum content blocker that users may install as an extension to block unwanted content while browsing the web, including advertisements, scripts, pop-ups, malware, crypto-miners, trackers, remote fonts, and more. It provides many benefits for users including lowered CPU usage, lowered memory usage, lowered network bandwidth usage, improved privacy, and improved security. uBlock Origin empowers users to take control of what is loaded and ran in their computer's web browser, providing users with a faster, safer, and less obtrusive web browsing experience.

Introduction of Manifest V3

In 2018, Google announced that it would begin a shift to a new version of Google Chrome extension manifest called Manifest V3, or MV3 for short, "to create stronger security, privacy, and performance guarantees." In 2020, Google released a beta version of MV3, and by early 2022, Google Chrome disallowed users to release extensions on the Chrome Web Store that were incompatible with MV3.

Due to the changes introduced in MV3, only uBlock Origin Lite — an incomplete version of the extension — is available to users of Google Chrome.

The phase-out then completed in stages. From March 31, 2025, all users had Manifest V2 extensions disabled by default, while still being able to turn them back on. With Chrome 138 (July 24, 2025), Manifest V2 extensions were disabled for all users on all channels, with no option to re-enable them; the ExtensionManifestV2Availability enterprise policy, the last workaround, was removed with Chrome 139. On August 31, 2026, all remaining Manifest V2 extensions were removed from the Chrome Web Store; copies still installed on Chrome 138 or earlier remain installed, but can no longer receive updates or be reinstalled. As a result, uBlock Origin no longer runs on current versions of Google Chrome.

Google's response

Google describes Manifest V3 as intended "to create stronger security, privacy, and performance guarantees", arguing that the previous blocking webRequest API was widely abused by malicious extensions.

The company implemented the phase-out gradually, which it presented as giving developers and users time to adapt: warning banners on the extension management page from June 2024, a disabling stage in which users could still turn extensions back on, enterprise exemptions via the ExtensionManifestV2Availability policy until Chrome 139, and only then full removal from the Chrome Web Store. Users of disabled Manifest V2 extensions were directed to the Chrome Web Store, where Manifest V3 alternatives were recommended; for uBlock Origin, the Manifest V3-compatible uBlock Origin Lite is offered, though it provides a subset of the original extension's functionality.

Consumer response

There are doubts that MV3 does much for the security, since according to the Electronic Frontier Foundation, "when a malicious extension sneaks through the security review process, it is usually interested in simply observing the conversation between your browser and whatever websites you visit". And to quote Firefox’s Add-On Operations Manager: "they can still do that with the current webRequest API that is not blocking".

Users can still browse the web without ads and with reduced tracking by switching to a browser which continues to support Manifest V2 and the full version of uBlock Origin, such as Mozilla Firefox or the Chromium-based Brave browser. As of August 2026, no workaround remains on current versions of Google Chrome, since the enterprise policy workaround was removed with Chrome 139 and remaining Manifest V2 extensions were removed from the Chrome Web Store.