Firefox Is the Last Major Browser That Still Supports uBlock Origin

With Chrome and Edge both dropping support for the most effective ad blocker on the web, your choice of browser now directly determines how much control you have over what you see online.

uBlock Origin no longer works on Google Chrome. Microsoft Edge is following the same path, with plans to phase out the extension by late 2026. That leaves Firefox as the last major browser where the full version of uBlock Origin still runs, PCWorld reports. Brave, which occupies a smaller niche, also continues to support the extension. But for the vast majority of internet users running a mainstream browser, the options just narrowed sharply.

This isn't just an ad-blocking story. It's a story about who controls the software layer between you and the web, and what happens when the company that makes your browser also runs the world's largest advertising network.

What Manifest V3 Actually Does

To understand why uBlock Origin is disappearing from most browsers, you need to understand Manifest V3, Google's updated framework for how browser extensions work in Chromium-based browsers.

The previous system, Manifest V2, gave extensions access to a powerful tool called the webRequest API. This let extensions like uBlock Origin intercept and inspect every network request your browser made in real time, then block the ones that matched known ad, tracker, or malware patterns before they ever loaded. It was fast, thorough, and gave extension developers fine-grained control.

Manifest V3 replaces webRequest with something called declarativeNetRequest. Instead of letting extensions actively monitor and filter traffic, declarativeNetRequest requires extensions to submit a static list of rules to the browser, which then handles the filtering itself. Google's stated rationale is security and performance: giving extensions less direct access to network traffic reduces the potential for malicious extensions to spy on users.

That rationale isn't baseless. Malicious browser extensions are a real problem. But the practical effect of declarativeNetRequest is that ad blockers become significantly less capable. The core differences break down like this:

• Manifest V2 (webRequest API): Extensions actively monitor and filter network traffic in real time, adapting to new ad and tracker patterns as they appear.
• Manifest V3 (declarativeNetRequest): Extensions submit a static, capped rule list to the browser, which handles filtering itself, with no real-time adaptability.
• Practical result: Static rule lists can't respond to the increasingly sophisticated techniques ad networks use to evade blocking, and their size limits restrict how comprehensive an extension's filtering can be.

uBlock Origin's developer, Raymond Hill, has been blunt about this. He created a stripped-down version called uBlock Origin Lite that works within Manifest V3's constraints, but has repeatedly noted that it cannot match the original's effectiveness, according to the project's GitHub wiki. The full version of uBlock Origin simply cannot function under the new framework.

The Browser Scorecard for Ad Blocking

So where does that leave users? As of mid-2026, the landscape breaks down like this.

Chrome: uBlock Origin no longer works. Google completed its Manifest V3 transition, and MV2 extensions are disabled. Users can install uBlock Origin Lite, but it's a meaningful downgrade.

Microsoft Edge: As Windows Central reported, Microsoft will start turning off MV2 extensions over the coming months, ending full uBlock Origin support by late 2026. Edge is built on Chromium, so it inherits Google's extension architecture. Microsoft chose to follow Google's timeline rather than maintain its own MV2 support.

Firefox: Mozilla has committed to continuing support for uBlock Origin. Firefox uses its own extension framework, independent of Chromium, and has no plans to drop the webRequest API that makes full ad blocking possible, according to Mozilla's own Manifest V3 FAQ. Firefox has explicitly said it will keep supporting the extension, according to PCWorld.

Brave: Windows Central reports that Brave also still supports uBlock Origin. Brave is built on Chromium but maintains its own modifications, including continued MV2 support and a built-in ad blocker. It's a viable option, though its market share is a fraction of Chrome's or Edge's.

For the roughly three-quarters of desktop users running Chrome or Edge, per Statcounter's global browser market share data, the default path is now a web with weaker ad blocking unless they actively switch browsers.

Why This Is About More Than Ads

It's tempting to frame this as a convenience issue. Ads are annoying; blocking them is nice. But the stakes are higher than that.

Modern web advertising doesn't just show you banners. It tracks your behavior across sites, builds profiles of your interests and habits, and feeds a data economy that most users never consciously opted into. Effective ad blockers like uBlock Origin don't just remove visual clutter. They block tracking scripts, prevent fingerprinting, and cut off data collection at the network level. That's a privacy tool, not just a comfort feature.

When the browser vendor controls which extensions can access network traffic, it controls the ceiling on what privacy tools can do. Google has a structural conflict of interest here: advertising accounts for the vast majority of Alphabet's revenue, according to the company's annual report. Designing an extension framework that limits ad blockers' effectiveness, even if the stated goal is security, directly serves Google's business model.

This doesn't require a conspiracy theory. It's just incentive alignment. Google built Chrome, Chrome dominates the browser market, and Chrome's extension rules now determine what's possible for most users. The result is that the company most invested in web advertising also sets the technical boundaries for tools that block web advertising.

Mozilla doesn't have that conflict. Firefox is funded partly through search engine deals, but Mozilla's core mission is explicitly about internet openness and user agency, as Mozilla states in its mission statement. Maintaining webRequest support is consistent with that mission, and it costs Mozilla nothing in ad revenue.

What Users Can Actually Do

If you're on Chrome or Edge and want to keep using full-strength uBlock Origin, your options are straightforward but require action.

Switch to Firefox. This is the most direct path. Firefox supports uBlock Origin fully, and importing bookmarks, passwords, and settings from Chrome or Edge takes a few minutes. Firefox's performance has improved substantially in recent years, and for most users the experience will feel familiar.

Switch to Brave. If you prefer a Chromium-based experience, Brave maintains uBlock Origin support and adds its own built-in blocking. The trade-off is a smaller ecosystem and some occasional site compatibility quirks tied to aggressive blocking defaults.

Use uBlock Origin Lite on Chrome or Edge. It works, but with reduced capability. You'll block some ads and trackers, but not with the same thoroughness as the full version. For casual users unwilling to switch browsers, this is the path of least resistance.

Consider mobile too. Firefox on Android supports uBlock Origin, which is unusual among mobile browsers, as listed on Mozilla's official add-ons page. Most mobile browsers, including Chrome on both Android and iOS, don't support full ad-blocking extensions at all. Open-source projects on GitHub are exploring alternative approaches — one example, the open-source Helium browser project, adds extension support on Android — though these remain niche.

For a browser-agnostic layer of protection, DNS-level tools like Pi-hole or NextDNS are worth considering, though they require more technical setup and can't match the page-level precision of a browser extension.

The Bigger Pattern

Firefox's position as the last major browser supporting uBlock Origin is a specific instance of a broader dynamic: platform owners increasingly control what software can do on their platforms, and users' ability to modify their own experience is shrinking.

Apple controls what apps can run on iPhones. Google controls what extensions can do in Chrome. Microsoft follows Google's lead on Edge. In each case, the platform vendor's incentives don't always align with the user's, and the user's leverage is limited to switching platforms entirely.

That switching cost is the key variable. Most people don't change browsers. They use whatever came with their device or whatever they set up years ago. The friction of switching is low in absolute terms but high in behavioral terms. Google and Microsoft know this.

Firefox's global browser market share remains small compared to Chrome, per Statcounter data. Whether this moment translates into meaningful user migration depends on whether enough people care about ad blocking to overcome that inertia. The answer will say something about how much autonomy users actually want over their own browsing experience, and how much they're willing to do to keep it.