Manifest V3 Ad Blockers: What Changed

Q: Does Manifest V3 affect Firefox?

No. Firefox uses its own extension standards and is not bound by Google's Manifest V3 policy. Mozilla has stated it will continue to support the webRequest blocking API in Firefox. uBlock Origin works fully on Firefox.

Q: What ad blockers still work on Chrome after Manifest V3?

Ad blockers built to use the Manifest V3 declarativeNetRequest API still work on Chrome. These include ProBlocker, AdGuard, AdBlock, Adblock Plus, and uBlock Origin Lite (a reduced-capability MV3 port of uBlock Origin). Chrome Stable began disabling Manifest V2 extensions in October 2024, and full uBlock Origin was no longer a supported Chrome option during that rollout.

Q: Why was uBlock Origin removed from Chrome?

uBlock Origin depended on the webRequest blocking API, which was removed under Manifest V3. The extension's developer concluded that the replacement declarativeNetRequest API imposed limitations that would compromise the extension's core capabilities. The full uBlock Origin was not ported to MV3 for Chrome. Chrome Stable began disabling MV2 extensions in October 2024.

Q: Is ProBlocker affected by Manifest V3?

No. ProBlocker was built from the ground up for Manifest V3 using the declarativeNetRequest API. It is available in the Chrome Web Store and is not subject to removal.

Q: What is declarativeNetRequest?

declarativeNetRequest is the Manifest V3 replacement for webRequest blocking. Instead of allowing an extension to intercept every network request and programmatically decide whether to block it, declarativeNetRequest requires the extension to pre-compile a set of rules. The browser applies these rules internally. This approach reduces the API surface available to malicious extensions, but also limits the flexibility available to ad blockers.

What Is Manifest V3?

Manifest V3 is the third version of the Chrome extension manifest format — the file that defines what an extension can do, what APIs it can access, and what permissions it requests. Google announced Manifest V3 in 2019 and began enforcing it in 2024.

The most significant change in MV3 relevant to ad blockers: the removal of the blocking variant of the webRequest API. Under MV2, an extension could intercept any network request the browser was about to make and cancel it before it was sent. Ad blockers used this to stop ad requests from reaching ad servers.

Under MV3, extensions must use the declarativeNetRequest API instead. This requires the extension to pre-compile a set of rules in a static format. The browser applies the rules internally. Extensions can no longer programmatically inspect or block arbitrary network requests in real time.

Why Manifest V3 Matters for Ad Blockers

The webRequest blocking API gave extensions complete visibility into outgoing requests, which enabled ad blockers to:

Apply complex, dynamic filter rules updated at runtime
Block requests to domains not in a pre-compiled list
Implement per-site exceptions with fine granularity
Support cosmetic filtering rules for element hiding

The declarativeNetRequest API limits rule sets to a maximum number of rules (extendable via dynamic rules, but with a cap). Extensions also cannot inspect request content or apply complex conditional logic at runtime.

This primarily affected uBlock Origin, which was considered the most capable ad blocker in part because it used dynamic programmatic filtering that MV3 cannot replicate.

What Happened to uBlock Origin on Chrome?

Chrome Stable began disabling Manifest V2 extensions in October 2024. uBlock Origin's developer Raymond Hill assessed the MV3 declarativeNetRequest API and concluded that a faithful port was not possible without significantly degrading the extension. He chose not to release a MV3 version of the full uBlock Origin for Chrome.

A separate project, uBlock Origin Lite, is a MV3 port that provides basic blocking capabilities. It lacks dynamic filtering, per-site exception rules, and some cosmetic filtering features present in the full uBlock Origin.

uBlock Origin remains fully functional on Firefox. Mozilla did not adopt Google's MV3 restrictions and continues to support webRequest blocking in Firefox extensions.

Does Manifest V3 Affect Firefox?

No. Firefox uses Mozilla's own extension standard and is not bound by Google's Manifest V3 policy. Mozilla has stated it supports the webRequest blocking API in Firefox extensions. uBlock Origin works fully on Firefox, including all dynamic filtering capabilities.

Edge, Brave, and Opera are Chromium-based and do follow Google's Manifest V3 standard, though enforcement timelines may differ from Chrome.

Ad Blockers on Chrome After Manifest V3

Ad blocker	Works on Chrome post-MV3	MV3 native	Notes
ProBlocker	Yes	Yes	Built for MV3 from launch
uBlock Origin (full)	Removed during the October 2024 rollout	No	Works on Firefox; not available on Chrome
uBlock Origin Lite	Yes	Yes	Reduced capabilities vs full uBlock Origin
AdGuard	Yes	Yes	Has Acceptable Ads by default
Adblock Plus	Yes	Yes	Has Acceptable Ads by default
AdBlock	Yes	Yes	Has Acceptable Ads by default

As of June 2026. Report an error

Frequently Asked Questions

What is Manifest V3?

Manifest V3 (MV3) is the third version of the extension manifest format used by Chromium-based browsers (Chrome, Edge, Brave, Opera). It replaces the older Manifest V2 standard and introduces a new API for network request handling that limits how ad blockers can intercept and block requests.

Does Manifest V3 affect Firefox?

What ad blockers still work on Chrome after Manifest V3?

Why was uBlock Origin removed from Chrome?

Is ProBlocker affected by Manifest V3?

What is declarativeNetRequest?

Install ProBlocker on Chrome

ProBlocker works on Chrome under Manifest V3 without workarounds or reduced functionality.

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