Google’s latest crackdown on browser extension has rendered popular ad blockers like uBlock Origin inoperable on Chrome, as the company pushes forward with its switch to Manifest V3.
The move, which critics say weakens privacy protections, affects all Chromium-based browsers, including Microsoft Edge. Meanwhile, Firefox is doubling down on its commitment to ad-blocking tools, promising to support both Manifest V2 and V3, ensuring users retain control over their browsing experience.
Manifest V3 is the newest version of Chrome’s extension framework but it has faced criticism for cutting off access to some of ad blockers’ functionality. It serves as the foundation for WebExtensions, which power browser APIs.
Google has defended Manifest V3, calling it “the first step in our platform vision to improve the privacy, security, and performance of extensions.”
Why won’t uBlock Origin work on Chrome?
uBlock Origin, a popular and highly customizable open source ad blocker, previously functioned on Manifest V2 through a feature called blockingWebRequest. Chrome has replaced blockingWebRequest with declarativeNetRequest, which restricts how extensions interact with web content.
Google first announced its plan to end support for extensions using Manifest V2 specifications in late 2023. A series of updates in early March further disabled extensions like uBlock Origin.
SEE: This Mac malware poses as a Safari or Chrome update.
Firefox will support both Manifest V2 and Manifest V3
Meanwhile, Mozilla says its Firefox browser will support both Manifest V2 and Manifest V3.
Mozilla Firefox held just 3.7% of the browser market in September 2024, but its dedicated user base prioritizes privacy and operability. Firefox has robust built-in ad blocking as well as supporting extensions like uBlock Origin. That loyal community has closely monitored changes to Firefox’s legal terms of use, which Mozilla updated earlier this week to clarify it does not own users’ content.
Firefox is standing firm in its commitment to privacy tools by allowing both blockingWebRequest and declarativeNetRequest.
“More tools for developers means more choice and innovation for users,” wrote Scott DeVaney, staff editorial manager for Firefox add-ons, and Ed Sullivan, community and developer relations manager for add-ons at Mozilla. “Giving people choice and control on the internet has always been core to Mozilla. It’s all about making sure users have the freedom to shape their own experiences online.”
