Chrome's transition to Manifest V3 forces uBlock Origin removal

Seven months after Google's September 2024 announcement regarding the transition from Manifest V2 to Manifest V3, users of uBlock Origin on Chrome are feeling the impact. The widely-used ad blocker is no longer supported on Google's browser, forcing millions of users to seek alternatives.

uBlock Origin's removal from the Chrome Web Store has sparked significant discussion among privacy advocates and everyday users alike. The extension, which enjoyed over 31 million users according to Chrome Web Store data, was discontinued because its core functionality relies on features no longer available in Chrome's new extension framework.

According to the Ghostery blog, "uBlock Origin was removed from the Chrome Web Store due to Google's transition from Manifest V2 to Manifest V3." This transition represents a fundamental shift in how browser extensions operate within Chrome's ecosystem.

The technical details behind this change are significant. Manifest V3 introduces a new extension framework designed to enhance security and privacy by limiting the execution of remote code. However, this same limitation severely restricts how ad blockers can function.

A September 26, 2024 post on the uBlock Origin website explained that "Manifest V3 is a significant update to the Chrome extension platform, introducing changes that impact how extensions interact with web content." The post further detailed that "One of the most significant changes is the modification of the webRequest API, which many content blockers use to intercept and modify network requests."

The core issue lies in how content blockers like uBlock Origin function. According to the technical documentation, "uBlock Origin relies heavily on the webRequest API to block unwanted content before it loads. Under MV3, the webRequest API is limited, and extensions are encouraged to use the new declarativeNetRequest API instead." This new API allows for predefined rules but lacks some dynamic capabilities that uBlock Origin utilizes for advanced content blocking.

For users seeking alternatives, several options have emerged. Ghostery's ad blocker has been adapted to work within the constraints of Manifest V3. AdGuard has also made their extension compliant with Manifest V3 in late 2024, though according to Ghostery, "AdGuard only blocks ads when you first install it. The extension won't block trackers, annoyances, or security threats without tinkering with the settings."

Another option is uBlock Origin Lite, a simplified version developed by the same team. The FAQ on the uBlock Origin GitHub repository clarifies that "uBO Lite is not meant as an MV3-compliant version of uBO, it's meant as a reliable Lite version of uBO, suitable for those who used uBO in an install-and-forget manner." However, it comes with significant limitations compared to the original extension.

User reviews on the Chrome Web Store reflect growing frustration. One review from April 5, 2025, states: "Geez. Now it's no longer available. Everyone needs to ask AI how to pack extensions." Another user commented: "It worked very well, that's why it's being squeezed out of being easily available now."

Many users have indicated they plan to switch browsers rather than seek alternatives. A review from April 4, 2025, declares: "The best ad blocker, still works, so if it stops working, I'll delete Chrome." Another from April 2 advises: "Thanks for all the good work you all have been doing and not putting up with Google's BS. This is a sign for whoever is reading this to ditch Chrome and move to better options such as Firefox."

Firefox emerges as the primary alternative for dedicated uBlock Origin users. According to the uBlock Origin website, "Firefox (and browsers built on Firefox) are the last remaining browsers that will support uBlock Origin fully. Adblockers are not restricted in Firefox like they will be in Chrome moving forward."

The technical differences between how Firefox and Chrome handle extensions are substantial. Firefox continues to support the webRequest API that uBlock Origin depends on, while Chrome has moved to the more restrictive declarativeNetRequest API.

On the uBlock Origin FAQ page, the developer explains filtering capabilities that cannot be ported to Manifest V3, including: "No remote fonts and no scripting per-site switches, Dynamic filtering, Dynamic URL filtering." Additionally, "The declarativeNetRequest API does not allow to filter according to the content of response headers," limiting other functionality.

The transition's timing has been known since 2021 when Google first announced the move to Manifest V3, but the full impact is only now being felt by everyday users. While Google maintains that the changes improve security and performance, critics argue it primarily benefits Google's advertising business by limiting the effectiveness of ad blockers.

For the marketing community, this change has several important implications. First, it potentially means more users will see advertisements on Chrome, which remains the dominant browser with approximately 65% market share globally. Second, it may accelerate browser fragmentation if significant numbers of privacy-conscious users migrate to Firefox or other alternatives.

Third, this change highlights the power major platforms have in controlling how users interact with content online. Marketing strategies heavily dependent on browser-specific behavior may need reevaluation, especially if user migration between browsers accelerates.

The situation also reflects the ongoing tension between advertising-based business models and user privacy preferences. As platforms introduce changes that impact privacy tools, marketers should monitor not just the technical implications but also shifting user sentiment and behavior.

Raymond Hill, the developer of uBlock Origin, has remained committed to the project despite these challenges. According to the uBlock Origin website, "As of 2025, uBlock Origin continues to be maintained and actively developed by founder and lead developer Raymond Hill." Notably, the project "still specifically refuses donations at this time, and instead advises all of its clients, users and supporters to donate to block list maintainers."

For users unwilling to switch browsers, the GitHub repository for uBlock Origin includes "temporary workarounds to re-enable the extension until June 2025." However, these fixes are described as "a stopgap solution rather than a long-term replacement for deprecated ad blockers."

The removal of uBlock Origin from Chrome represents a significant shift in the browser ecosystem and how users control their online experience. While alternative solutions exist, none offer the full functionality and customization that made uBlock Origin popular among privacy-conscious users.

Timeline

• 2021: Google announces plans to transition from Manifest V2 to Manifest V3
• September 26, 2024: uBlock Origin publishes explanation of Manifest V3 impact
• Late 2024: AdGuard makes their extension Manifest V3 compliant
• Early 2025: Chrome begins disabling Manifest V2 extensions
• April 2025: uBlock Origin no longer supported in Chrome Web Store
• June 2025: Temporary workarounds to continue using uBlock Origin on Chrome expected to stop working