Google is finalising its shift to Manifest V3, a move that ends the loophole that let legacy ad blockers survive. The change removes the Extension Manifest V2Disabled flag, a key escape hatch used by tools like uBlock Origin. Chrome 150, slated for June 30, 2026, will cut the flag from the browser.

The decision follows years of criticism that Manifest V3’s tighter permissions would cripple ad‑blocking extensions. Chrome 151, expected July 2026, will drop remaining MV2 flags—Extension Manifest V2Unsupported, Extension Manifest V2Availability, and Allow Legacy MV2Extensions—completing the phasing out of all second‑generation extensions. This move removes a major source of security bugs that Google recently discovered in legacy code, tightening the browser’s overall stability today.

Other Chromium‑based browsers can keep MV2 support, but Microsoft Edge and Opera are likely to follow Chrome’s path. Power users who relied on the flag now face a hard stop; manual workarounds via Dev Tools are impractical for daily use and offer no long‑term solution. Consequently, developers must pivot to architectures or accept privacy controls.

With MV2 extensions no longer permitted in any supported Chrome version, the browser’s attack surface shrinks and developers gain a clearer path to build privacy‑friendly extensions. The removal marks the end of a decade‑long legacy that many users and security teams had to patch manually. This shift consolidates security policies and eases compliance for deployments.