Navigating Google Chrome’s Manifest V3🚀 Tips for Ad Blockers & Solutions

Google has initiated one of the most critical transitions in its browser extensions by implementing Manifest V3 (MV3) in Chrome, the latest version of the extensions platform. First announced in 2018, MV3 officially launched on 3 June 2024; this transition was primarily designed to improve security, performance, and privacy. However, it has also sparked concerns among developers and users who use ad blockers. But how has MV3 impacted so far? Have adblockers stopped working altogether? Let's analyze the impact of MV3 on ad blockers and share some tips for users encountering browsing functionality issues.

Key Changes in Manifest V3 for Chrome Extensions

MV3 is the new application programming interface (API) version that Google Chrome uses for its extensions, changing how they interact with the browser. Among the most relevant changes are:

Reduced use of permissions

V3 extensions have more limited access to browser data and functionality. To minimize security risks, extensions must now specify the domains for which they need access to permissions. 

Service workers instead of background pages

Background pages are hidden pages that remain permanently active, which can consume significant system resources. In contrast, service workers are scripts that run in the background only when necessary. This change helps reduce memory consumption and improve overall browser performance.

Declarative NetRequest API

The new Declarative NetRequest API offers an improved method for filtering and modifying network requests securely and efficiently. It defines rules to block, alter, or allow specific network requests based on user permissions.

This new transition aims to make Google Chrome extensions more secure and efficient. However, it has also restricted some functionalities that allow ad blockers to be so effective, causing unease among developers and users. Let's explore some specific implications for developers below.

Challenges Faced by Developers Under Manifest V3

Google has published detailed migration guides from Manifest V2 to Manifest V3 extensions and support resources such as code samples, tutorials, FAQs, and active online support to help developers adapt their extensions to the new MV3. Still, developers are facing various challenges:

• Extension Compatibility: This transition has affected some extensions' functionality and compatibility; sometimes, they may even stop working for some users. For example, videos may stop playing when the extension is active on platforms like YouTube.
• "Untrusted" Labels: Also, due to the new restrictions, some extensions are labeled as "Untrusted by Enhanced Safe Browsing," making users hesitate to install them.
• Frequent Script Restarts: Another change observed after the Manifest V3 implementation is that the browser background script restarts more frequently. Frequent restarts may alter the functionality of extensions that rely on continuous background script execution, which could affect the experience for some users.

MV3 and Its Impact on Ad Blockers

One of the most notable changes introduced by MV3 is the removal of the "webRequest" API for the "Declarative NetRequest." The "webRequest" API is an interface used in web browser extensions to intercept, block, and modify network requests. It allows extensions to control network traffic and how web requests are handled, which is crucial for ad blocking.

However, the “Declarative NetRequest” changes mean extensions use a predefined rule-based API to handle network requests. The browser processes these rules, reducing the need for extensions to access and modify network requests directly. In addition, MV3 limits the filtering capability to 30,000 rules (rules that define which network requests should be blocked, altered, or allowed), which is far below the approximately 300,000 used by popular ad blockers. As a result, ad blockers find it challenging to filter network requests to block ads, reducing their effectiveness.

For example, Stands Adblocker experienced declining ad-blocking quality on YouTube due to new limitations imposed by Manifest V3. uBlock Origin is also affected by the new Declarative Net Request API because it implements more complex filtering than most adblockers, and AdGuard is now operating with 5,000 rules instead of 30,000 to fit within these limitations. 

Strategies for Users to Cope with MV3 Restrictions

But then, what can users do now to cope with the new MV3 restrictions? Through platforms like Reddit, users have shared some (perhaps temporary) alternatives to cope with these MV3-related issues regarding ad-blocking extensions. Several users recommended using browsers that do not implement MV3. For example, the Vivaldi browser will keep the Manifest v2 for as long as it's available in Chromium. Brave also continues to support some privacy-relevant MV2 extensions and currently has no plans to implement MV3.

We also recommend using ad blockers that have adapted to the MV3 transition. After June 3rd, some third-party ad blockers successfully upgraded through the Manifest V3 switch. For example, Stands Adblocker prioritized rapid improvements and released four major product updates to improve ad-blocking effectiveness. Stands has maintained its Feature Badge after the MV3 since it aligns with the new Chrome Web Store best practices.

On the other hand, AdGuard developed a new ad-blocking extension designed to comply with the constraints of Manifest V3 and operate effectively under these new conditions. Adblock Plus has also adapted to Manifest V3 by limiting the number of filter lists available and maintaining its "Feature Badge."

Although third-party adblockers have adapted to the MV3 transition, they may still present occasional technical problems due to the nature of MV3. We therefore recommend that you keep up to date with the latest updates to your favorite adblocker. 

Conclusion on Manifest V3 Impact

Google Chrome's implementation of Manifest V3 marks a significant change in the functionality of browser extensions, with substantial implications for ad blockers. Despite the challenges, developers and users have managed to adapt. Whether opting to explore browsers that do not implement Manifest V3 or using MV3 adaptive ad blocker solutions, users can now optimize their browsing experience during this transition.

Navigating the impact of Chrome's Manifest V3 transition requires resilience and adaptability. Stay informed and proactive to ensure a seamless browsing experience.