Overview
- A Chromium code commit removed the kExtensionManifestV2Disabled flag and a Google engineer confirmed that Manifest V2 extensions are no longer allowed in supported Chrome releases.
- Chrome 150 is expected to remove the primary MV2 workaround around June 30, 2026, and Chrome 151 is slated to strip the remaining MV2 flags in July 2026, which together will end practical MV2 support in Chrome.
- Manifest V3 replaces MV2’s dynamic background filtering with a stricter, rule-based model that limits how many blocking rules an extension can load and prevents extensions from intercepting traffic in the same way.
- The near-term effect is that long-standing ad blockers built for MV2, including the original uBlock Origin, will stop working in Chrome unless rebuilt for MV3, while MV3-compatible options such as uBlock Origin Lite will continue to function.
- Other Chromium-based browsers can choose their own path but are likely to follow Chrome’s timetable, and users who want to keep legacy blocking behavior can switch to non‑Chromium browsers like Firefox or Brave.