Overview
- Microsoft started the MV3 rollout this month and says it will complete the switch for private users by the end of 2026 and finish enterprise migration in 2027.
- Manifest V3 replaces programmatic request blocking with the declarativeNetRequest API, requiring extensions to supply rules that the browser enforces rather than letting extensions intercept network traffic directly.
- The classic MV2 version of uBlock Origin will no longer work in Edge; only a reduced MV3 'uBlock Origin Lite' exists and users who want the original must move to a browser that still supports MV2.
- Microsoft will remove MV2 extensions progressively, show in-browser notices to affected users, and notify developers through the Partner Center, and it currently reports 58 MV2 extensions remaining in the Edge Add‑On Store.
- Chrome completed its MV3 transition in 2025, while other vendors vary in response—Opera plans extended MV2 support, Brave will keep selected MV2 extensions, and Mozilla will support both—creating uneven options for users and developers and likely prompting more browser switching or porting work.