What Chrome’s Manifest V2 deprecation means for ad blockers
Chrome’s Manifest V2 deprecation is the phased removal of an older extension framework that allowed powerful, real‑time ad blocking and tracking protection, replacing it with Manifest V3, which limits how extensions can filter web traffic and control page content. For users, this shift turns the quiet “This extension is no longer supported” banner into a hard stop. Around 40 million people still run the original uBlock Origin on Chrome, and their setup depends on Manifest V2’s per‑request filtering. Chrome 150 removes the internal flag that kept these legacy extensions alive, while Chrome 151 strips out remaining Manifest V2 code so full‑fat blockers no longer load at all. Google frames Manifest V3 as a security and performance upgrade, but for power users it is a clear loss of fine‑grained control over what their browser loads.
How Chrome 150 and 151 will cripple uBlock Origin
Chrome ad blocker removal is happening in two steps that target uBlock Origin and similar tools. The first blow lands with Chrome 150, which removes the ExtensionManifestV2Disabled flag that let determined users keep classic blockers running past their official cutoff. The second comes with Chrome 151, which removes all remaining Manifest V2 code paths. At that point, “the original uBlock Origin — the gold standard of ad blocking for millions — simply stops loading.” Manifest V2 allowed extensions to intercept and cancel ad and tracker requests before a page rendered, using large and dynamic blocklists. Under Manifest V3’s declarativeNetRequest system, Chrome controls the rules engine and limits on‑the‑fly filtering. Users can move to uBlock Origin Lite or other MV3 blockers, but they must accept reduced capabilities and less precise control over ads, trackers, and content.
Firefox stays open for full-featured ad blocking
While Chrome tightens extension rules, Firefox ad blocking remains based on a more permissive model that still allows uBlock Origin’s full capabilities. Firefox 152 continues Mozilla’s fast release cycle, adding a redesigned Settings page and quality‑of‑life updates like a Quick Action that mutes all noisy tabs when you type “mute,” “sssh,” or “hush” in the address bar. It also introduces experimental JPEG XL support and better tools for sending or copying one or many tabs. Crucially, Firefox has not adopted Chrome’s Manifest V3 limits, so MV2‑style dynamic filtering stays intact on Gecko‑based browsers. That means users can keep using the original uBlock Origin without worrying about MV2 deprecation dates or enterprise policy workarounds. For people who care about fine‑tuned blocking, script control, and custom rules, Firefox now looks like the path of least resistance.
Why power users and privacy fans are eyeing Firefox
For power users, Chrome ad blocker removal highlights a broader clash between browser vendors’ ad revenue interests and user demands for strong blocking tools. Google stresses that Manifest V3 improves “security, privacy, performance and trustworthiness,” and notes that over 85 percent of actively maintained Chrome extensions have already migrated. Critics point out that the world’s largest advertising company is also weakening the tools that most effectively block its main revenue stream. At the same time, Chromium‑based browsers such as Edge and Opera are expected to follow Chrome’s Manifest V2 deprecation because they share the same upstream code. That leaves Firefox as the main ad blocker alternative for users who want full extension control. With Chrome 150/151 limiting uBlock Origin Chrome 150 users and cutting MV2 entirely, Firefox stands out as the stable home for serious ad and tracker blocking.
