Google Removed Manifest V2 Extensions: What It Means for uBlock Origin

At some point, browser maintenance feels like housekeeping: an update arrives, your tabs survive, and you keep browsing. Then you open the Chrome Web Store to reinstall uBlock Origin and the listing is gone. On August 31, 2026, Google removed the last remaining Manifest V2 extensions from the store, including the original uBlock Origin (uBO), an open-source, wide-spectrum content blocker that filters ads, trackers, and other unwanted page activity.

That date was the final storefront milestone, not the beginning of the change. Google disabled Manifest V2 for ordinary Chrome users with Chrome 138 on July 24, 2025, and Chrome 139 removed the remaining enterprise exception. A copy installed on Chrome 138 or earlier may remain in that old browser profile, but Google says it cannot receive updates and cannot be reinstalled from the store after removal. That is a local-retention rule, not a promise that modern Chrome will continue running it.

What Manifest V2 actually describes

An extension manifest is a configuration file that tells a browser what an extension is allowed to do: which pages it can access, which permissions it requests, what background code it uses, and where its settings live. Manifest V2 and Manifest V3 are two generations of that extension platform, not version numbers for uBlock Origin itself. Moving from one to the other changes the extension's operating model.

To see why uBO is caught in this transition, picture a page loading. The browser sends network requests for the document, images, stylesheets, and scripts. A content blocker can stop some of those requests before they reach a server, redirect them, or hide unwanted pieces of the page after it begins rendering. uBO combines those jobs with filter lists, which are collections of text rules maintained for blocking ads, trackers, malware domains, and page elements.

Google's case for Manifest V3

Google designed MV3 around tighter control over extension code and background work. In MV2, an extension could keep a long-lived background page running. MV3 replaces that with a service worker, a short-lived background program that wakes when needed and can be stopped when idle. MV3 also disallows remotely hosted code, so an extension must package the JavaScript it executes instead of downloading new executable code from a server.

The largest change for blockers is network filtering. MV2 extensions could listen for a request and make a decision while it was in flight through the blocking form of the webRequest API. A simplified example looks like this:

chrome.webRequest.onBeforeRequest.addListener(
 => ({ cancel: true }),
 { urls: ["*://ads.example/*"] },
 ["blocking"]
);

The extension receives a matching request and returns a decision. In MV3, most normal store extensions must describe the decision ahead of time with the declarativeNetRequest API. "Declarative" means the extension supplies rules and conditions, while the browser owns the matching and enforcement:

[
 {
 "id": 1,
 "priority": 1,
 "action": { "type": "block" },
 "condition": {
 "urlFilter": "ads.example",
 "resourceTypes": ["script"]
 }
 }
]

This arrangement can reduce persistent work and make permissions more predictable. It also puts boundaries around the rule language, available actions, and rule quotas. The blocking permission in webRequest remains available for extensions installed and managed by an organization, but it is not available to most ordinary MV3 extensions.

Why uBlock Origin feels different under MV3

Content blocking is a demanding test because it is not one feature. The original uBO supports network rules, per-site controls, cosmetic filtering—which means hiding page elements such as ad boxes—script-based countermeasures, and detailed ways to allow one request while blocking another. Some of those decisions depend on the page that initiated a request, response details, or logic that does not fit neatly into a predeclared rule.

That does not make MV3 blocking useless. An MV3 blocker can still remove many ads and trackers, and the browser can apply fully declarative rules reliably while it starts. The trade-off is that it cannot reproduce every advanced behavior of the original extension, especially on sites that fight content blockers or require careful exceptions.

The question many users are now searching is: Is uBlock Origin Lite the same as uBlock Origin? No. uBO Lite is a separate MV3 extension built around declarative filtering and a lightweight service worker. It has gained capabilities such as custom filters and external filter-list subscriptions, but its own project describes it as a Lite version rather than an automatic replacement. For an install-and-forget setup, the difference may be hard to notice; for advanced per-site tuning, it can be substantial.

What the removal means in practice

For Chrome users, the path forward is to choose an MV3 blocker, such as uBO Lite, based on the features and permissions that matter to them. Downloading an old MV2 package from an unfamiliar website will not restore the original behavior in modern Chrome, because the obstacle is browser support, not only the missing store listing. The removal also creates a good moment to avoid lookalike extensions with similar names and inspect the publisher before installing anything.

Firefox remains the clearest route for people who want the original uBO experience. The project maintains uBO for Firefox and says it works best there, including on desktop and Android. Firefox uses its own browser engine rather than Chromium, so Google's MV2 shutdown does not dictate Firefox's extension architecture.

Brave takes a different approach. Its built-in Brave Shields blocks ads and trackers inside the browser, without relying on an extension manifest at all. Brave also documents a separate, best-effort way to host four selected MV2 extensions—AdGuard, uBlock Origin, uMatrix, and NoScript—outside the Chrome Web Store. That illustrates an important distinction: a browser can inherit Chromium's code while making its own product decisions about privacy features and extension support.

Other Chromium-based browsers can land somewhere between those examples. A browser built on Chromium may use the Chrome Web Store for discovery and installation, so Google's removal can affect what users can find even when that browser has a different runtime policy. Microsoft Edge, for example, began its consumer MV2 transition in August 2026 and has said it aims to complete that rollout by the end of 2026. Chromium is a family resemblance, not a promise that every browser handles extensions identically.

The bigger lesson

Google's decision is not really about one blocker icon. It settles where authority lives: MV2 let extension code stand beside the network pipeline and make decisions as requests arrived, while MV3 asks the browser to enforce a predeclared set of rules and limits long-running code.

For users, browser choice is now part of privacy configuration. If ordinary ad and tracker blocking is enough, an MV3 extension may fit well. If broad, highly customizable filtering matters, a browser that preserves the original uBO environment—or provides a native blocker with similar reach—is a better match.

The Chrome Web Store shelf has been cleared, but the deeper change happened inside the browser. uBlock Origin was not made irrelevant; the platform contract it was built for was retired.