uBlock Origin Will Soon Stop Working in Google Chrome

Google Chrome is recommending that uBlock Origin users switch to other ad blockers, as all Manifest v2 extensions will soon be disabled as part of the transition to Manifest v3. According to Raymond Hill, the lead developer and maintainer of uBlock Origin, after updating to Google Chrome 127, users have started seeing warnings about the upcoming end of support for the blocker. This is due to the imminent shutdown of the Manifest v2 extension platform.

Since there is no Manifest v3 version of uBlock Origin, the browser suggests alternative extensions as replacements. When following the provided link, users are directed to a page recommending they switch to uBO Lite, Adblock Plus, Stands AdBlocker, or Ghostery.

The mentioned uBO Lite (uBOL) was recently introduced by the uBlock Origin developers. As the name suggests, this extension supports Manifest v3. However, the developers have warned that while it may suit many users, it cannot fully replace uBlock Origin. More advanced users may need to configure additional settings or grant extra permissions to specific sites.

“Focusing on reliability and efficiency in the Manifest v3 environment meant sacrificing many features that cannot be implemented within Manifest v3,” the uBlock Origin team wrote. As a result, the developers have prepared a special FAQ explaining the differences between the current extension and uBOL, the new Manifest v3 version.

Warnings about the upcoming end of support for Manifest v2 extensions are now being seen by users of many other products as well. In June 2024, the transition to Manifest v3 finally began—a process Google has been preparing for years. The next step after showing warnings will be the gradual disabling of v2 extensions, with users being recommended alternatives. It is expected that users will be able to temporarily re-enable their Manifest v2 extensions, but this option will soon be removed entirely.

The transition to Manifest v3 is expected to be fully completed by early 2025.

What Is Manifest v3?

Manifest v3 is the new version of the extension platform, which Google claims is designed to improve the security, privacy, performance, and overall reliability of Chrome extensions. Manifest v3 aims to:

• Limit extension access to users’ network requests
• Require developers to include all functionality within the extension itself, ending the practice of remote code hosting
• Move network request modification from extensions into the browser itself
• Replace background pages with special workers to improve browser performance

The main issue with Manifest v3, which the community has been actively discussing since 2018, is that it creates serious technical challenges for extension developers and makes it harder for ad blockers, antivirus tools, parental controls, and privacy protection products to function effectively.

Because of this, the Electronic Frontier Foundation (EFF) has called Manifest v3 “deceptive and dangerous,” stating that “Mv3 is unlikely to significantly improve [user] protection.” In a later article, EFF representatives also noted that Google’s argument about “lower resource usage” does not hold up to scrutiny. Mozilla experts have reached similar conclusions. Firefox will support Manifest v3, but the browser does not plan to disable support for Manifest v2.

Back in 2022, the developers of the AdGuard ad blocker detailed the risks of switching to Manifest v3 and the problems they faced when creating a new version of their blocker. In short: the filtering rule limits were insufficient, the syntax for declarative rules was very restricted, users could not view filtering logs, and the changes caused performance issues.

One of the main problems is that rulesets can no longer be regularly updated by the extension itself through automatic updates. Instead, updates will only occur when new extension versions are released, meaning any update requires submitting a new version to the Chrome Web Store, which may trigger a security review lasting several weeks. As a result, for example, YouTube can instantly change its ad delivery system, but once Manifest v3 becomes mandatory, extension developers will not be able to respond to these changes quickly.

Skepticism about Manifest v3 is mainly due to concerns about “content filtering” and the APIs used by ad blockers and anti-tracking extensions—tools that advertising companies, including Google, are interested in limiting. Google, which currently earns about 77% of its revenue from advertising, has yet to provide a serious explanation for why Manifest v3 restricts content filtering, and it remains unclear how this aligns with the stated goals of “improving security, privacy, performance, and reliability.”

However, Google claims to have listened to developer feedback and made necessary improvements to Manifest v3. These include support for user scripts, offscreen documents, and increasing the number of allowed rulesets for declarativeNetRequest. Other recent key changes include the ability to skip reviews for rule updates and version rollbacks, giving developers more control over updates.

In June of this year, Google reported that as a result of its efforts to accelerate Manifest v3 adoption, over 85% of actively maintained Chrome extensions (including popular ad blockers like AdBlock, Adblock Plus, uBlock Origin, and AdGuard) have already migrated to Manifest v3 or released versions that support it. Developers whose extensions still run on Manifest v2 have been “strongly encouraged” by Google to complete migration as soon as possible.