Chrome Deletes Last MV2 Extensions
- Chrome's Manifest V2 extensions stopped executing on stable Chrome in July 2025 when Chrome 138 removed the final re-enable toggle; the August 31 date marks only the deletion of
- uBlock Origin's full MV2 version no longer runs on Chrome; a reduced Manifest V3 variant, uBlock Origin Lite, is available, while the original continues to operate on Firefox,
- Microsoft announced on 7 August 2026 that Edge will deprecate MV2 for consumers by end of 2026, removing it as a long-term refuge for users of MV2-dependent extensions.
Countdown timers have reappeared on technology blogs, ticking towards 31 August 2026 and warning that Chrome is about to destroy your extensions. The alarming framing is misleading. The functional part of Chrome's Manifest V2 deprecation — the change that actually stopped old extensions running — took effect more than a year ago. What happens at the end of this month is a database housekeeping exercise at the Chrome Web Store.
What the August 31 deadline actually means
On 31 August, Google will remove remaining Manifest V2 listings from the Chrome Web Store. Extensions still installed on very old Chrome builds will stay put but will no longer receive updates and cannot be reinstalled once their store pages are deleted. Nothing changes in the browser itself, because on any current version of Chrome the affected extensions have already been unable to run since mid-2025.
The real timeline: when MV2 actually died
Manifest V2 was the extension format Chrome used for over a decade, having launched in 2012. Its successor, Manifest V3, reached stable Chrome on 19 January 2021, and Google spent the following years systematically closing every path that allowed the older format to keep running. The pivotal date was 24 July 2025, when Chrome 138 disabled MV2 for all users on all channels and removed the manual re-enable toggle. The very next release, Chrome 139, deleted the enterprise administrator policy that had kept MV2 alive on managed machines, closing the final door. Chrome 150 and 151, released across June and July 2026, removed remaining developer flags and command-line switches, though those steps affected only developers working on custom builds and were not included in Google's official deprecation timeline; they are drawn from Chromium commit records and contemporaneous technical reporting.
The practical consequence is straightforward: any extension running in Chrome today is already Manifest V3. If it works, it has already made the transition.
Three changes — and one genuine grievance
Google's case for Manifest V3 rested on three technical changes. The first bans remotely hosted code. Under MV2, an extension could fetch and execute JavaScript from an external server after passing review, meaning the code Google examined and the code running in a user's browser could differ entirely. MV3 requires all executable logic to ship inside the reviewed package. This is widely regarded as a straightforward security improvement.
The second change replaced the blocking webRequest API with declarativeNetRequest. Under MV2, an extension could intercept every network request the browser made and decide in real time, via its own JavaScript, whether to allow, block, or modify it. MV3 instead requires extensions to submit a rulebook in advance; Chrome's own network stack enforces those rules without ever exposing request data to extension code. Google's argument is that this protects user privacy and improves performance. The uncomfortable counterpoint is that the company making that argument also sells advertising, and critics contend that a stricter permission model or a more narrowly scoped API could have achieved the same privacy benefit with less collateral damage to advanced content-blocking tools. The declarativeNetRequest API caps static rules at a guaranteed minimum of 30,000, with a matching dynamic allowance — a budget Google has raised more than once in response to complaints. Even so, declarative rules cannot replicate logic that depends on inspecting a response's contents or chaining conditional decisions the way live code can.
The third change replaced persistent background pages with ephemeral service workers that Chrome terminates after roughly 30 seconds of inactivity. The motivation is memory efficiency. The cost for developers was a significant rewrite of any extension that relied on persistent in-memory state, though the change is now simply the platform's baseline.
uBlock Origin: what remains and where
Raymond Hill's uBlock Origin — the version built on MV2's blocking webRequest — stopped running on Chrome when Chrome 138 disabled MV2 in July 2025. Hill has produced a Manifest V3 version, uBlock Origin Lite (uBOL), which pre-compiles filter lists into static rulesets and blocks most common advertising on most sites. Hill has not claimed it is a full equivalent; it lacks the dynamic, per-site filtering and adaptive cosmetic-filtering capabilities of the original.
The original uBlock Origin continues to run unmodified on Firefox, which has retained the blocking webRequest API. Brave Browser handles ad and tracker blocking natively within its own network stack via a Rust engine, placing it outside the scope of Chrome extension rules entirely. AdGuard also offers a standalone application that filters at the system level.
Microsoft Edge had been a temporary refuge: built on Chromium but without Chrome's MV2 cut-off, it continued to run the full uBlock Origin until recently. On 7 August 2026, however, Microsoft announced that Edge would begin its consumer transition away from Manifest V2 in August 2026, starting on pre-release channels and reaching the stable channel in subsequent months, with the consumer phase targeted for completion by the end of 2026. Enterprise devices are not affected during that rollout; a separate enterprise deprecation is planned for early 2027. Firefox remains the only major browser that has committed to retaining both Manifest V2 support and the blocking webRequest API.
The upshot
For the overwhelming majority of Chrome users, 31 August 2026 will pass without incident. The extensions they rely on have already been running on Manifest V3 for more than a year. The substantive argument — whether the switch from blocking webRequest to declarativeNetRequest was an unavoidable privacy trade-off or a disproportionate restriction that happened to suit Google's advertising interests — was settled in practice last summer, even if the debate has not quietened since.
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