If you use an ad blocker on Google Chrome, you might be wondering whether the new Manifest V3 update will disrupt your ad-free browsing experience. But before we dive into Manifest V3, let’s first understand what a Manifest is. In Chrome extensions, a manifest is like a set of instructions that tells the browser everything it needs to know about the extension. It explains:
- What the extension does (e.g., blocking ads or saving passwords).
- What permissions it needs (e.g., accessing websites).
- How it should work within the browser.
The manifest acts as a blueprint that helps the browser understand and control how extensions function.
Google’s latest update, Manifest V3, introduces new rules to make extensions safer and faster, but it also limits what some tools, like ad blockers, can do.
So, how does this affect you? In this blog, we’ll break down what Manifest V3 is, how it impacts ad blockers, and what it means for your browsing experience.
What Is Manifest V3?
Manifest V3 is Google’s latest update to the rules for Chrome extensions. It’s designed to make extensions safer, faster, and better at protecting your privacy. These new rules focus on improving security by limiting what extensions can do, which helps prevent harmful or malicious extensions from abusing their powers.
Under Manifest V3, extensions must follow stricter guidelines. For example:
- Extensions can no longer load or update code from outside sources (this prevents bad actors from sneaking in harmful code).
- Ad blockers and similar tools must use pre-approved blocklists to block content, instead of deciding what to block in real-time.
- Extensions are optimized to use less memory and run more efficiently, making your browser faster.
However, while these changes make extensions safer, they also reduce the flexibility and power of some tools, which may no longer work as effectively as they did under the Manifest V2.
Why Did Google Make These Changes?
Google aims to reduce the risk of malicious extensions that exploit vulnerabilities by making the changes on Manifest V3. However, critics argue that these changes might also serve Google’s financial interests. Since Google’s revenue heavily relies on ads, weakening ad blockers could mean more ad impressions and higher profits for the company.
Comparison of Manifest V2 and Manifest V3
Here’s a side-by-side look at the key differences between Manifest V2 and Manifest V3, explained in simple terms:
| Feature | Manifest V2 | Manifest V3 |
| Ad Blocking API | Ad blockers can check each website element in real-time and block ads on the spot. | Ad blockers now work with a pre-written blocklist, some ads may slip through. |
| Code Execution | Extensions could update or add features on the fly, making them flexible but less secure. | Extensions can no longer update dynamically, improving security but reducing flexibility. |
| Rule Limits | No limit on blocklists, allowing extensions to block more ads and unwanted content. | Limit of 30,000 ads for blocklists, which may reduce how many ads extensions can block. |
| Performance | Real-time blocking could slow down your browser. | Pre-loaded rules make extensions faster and improve browser performance. |
| Security | Allowed remote updates but left room for harmful code. | Stricter rules ensure all code is pre-approved, reducing risks. |
So, in simple terms, Manifest V3 improves security and performance. However, due to the limitations on ad blocklists, ad blocker extensions have been affected and lack comprehensiveness, which may allow more ads to slip through. Additionally, extensions are now more secure with stricter rules, but they have lost the ability to update dynamically.
What’s Happening With Ad Blockers and Manifest V3?
How Did Ad Blockers Work Before?
Under Manifest V2, ad blockers could examine all website requests in real-time, identify which ones were ads, and block them. It was like having a security guard at a party door, spotting the troublemakers and stopping them from entering—all of this relied on the webRequest API.
What’s Changing for Ad Blockers With Manifest V3?
With Manifest V3, ad blockers must use the declarativeNetRequest API. This new system works differently:
- The security guard no longer decides on the spot (not the real-time).
- Instead, you must give the guard a pre-approved list of guests before the party starts.
This change poses several challenges:
- Larger Limits of Blocklists: Ad blockers are now limited to 30,000 ads, but most require up to 300,000 ads to work effectively.
- Less Flexibility: Under Manifest V2, ad blockers could instantly update their rules if new ads appeared. Now, they must submit updates to Google for approval, which takes time.
- Reduced Collaboration: Ad blockers can no longer combine blocklists from different providers or sources as easily, which reduces their overall effectiveness.
Which Ad Blockers Work Well Under Manifest V3?
Despite the challenges, some ad blockers have already adapted to Manifest V3 and continue to provide effective ad-blocking. Here are three ad blockers that work well under Manifest V3:
| Ad Blocker | Adaptation to Manifest V3 | Why It’s Great |
| ⭐ AdGuard | Preloaded blocklists to comply with the rule limit. | – Strong blocking – Regular updates |
| ⭐⭐ uBlock Origin Lite | Lightweight version designed for speed and compliance. | – Faster browsing – Pre-approved blocklists – Reduced flexibility |
| ⭐⭐⭐ Ghostery | Updated to ensure privacy-focused blocking. | – Blocks ads and trackers – Privacy insights – User-friendly interface |
These ad blockers have adjusted their designs to align with Manifest V3’s requirements while continuing to offer decent ad-blocking functionality.
What Other Effects Will Manifest V3 Have?
While ad blockers are the most talked-about extensions affected by Manifest V3, the changes impact other types of extensions too:
Enhanced Security Measures:
Extensions can no longer load or update code from outside the extension itself, which helps prevent malicious attacks. However, this also limits extensions that rely on real-time updates.
For more security tips about Google Chrome extension, we prepare this blog for you: Are Chrome Extensions Safe? Secure Tips for You in 2025
Performance Improvements:
With the new pre-loading mechanism for blocklists, Chrome will consume fewer resources, resulting in faster browsing.
Impact on Privacy Tools:
Extensions like VPNs or privacy trackers may face restrictions in how they operate due to Manifest V3’s stricter rules. These rules, such as limiting dynamic code execution and requiring pre-approved functionality, can reduce the flexibility of some privacy tools. However, not all VPN extensions are affected equally—some, like X-VPN, have fully adapted to Manifest V3 while continuing to provide reliable privacy protection.
Developer Challenges:
Developers must rewrite their extensions to comply with MV3, which requires significant time and resources. Some extensions may be discontinued if developers are unable to adapt.
Conclusion
Manifest V3 marks a major shift in how Chrome extensions work. While it promises better security, performance, and privacy, it also introduces significant limitations for ad blockers and other popular extensions. For users, this means you may notice more ads slipping through and fewer options for certain tools.
Google has made Manifest V3 mandatory, so all extensions must comply by mid-2024. While some users may explore alternative browsers like Firefox (which still supports Manifest V2), others may need to adjust to these changes in Chrome.
FAQs
1. What does Manifest V3 mean?
Manifest V3 is an updated set of rules for how Chrome extensions work, focusing on improved security, performance, and privacy.
2. Why is Manifest V3 bad for ad blockers?
It limits the number of ads they can block and reduces their flexibility to update rules in real-time, making them less effective.
3. Is Manifest V3 mandatory?
Yes, Google has made Manifest V3 mandatory for all Chrome extensions. Developers must transition by mid-2024.
4. Will Ad Blockers Stop Working?
No, ad blockers won’t stop working, but they may not be as effective. You might notice some ads slipping through due to the reduced rule limits and slower update processes.
