The Year of Firefox: Google initially announced the Manifest V3 API in 2018, but the new extension technology was delayed several times because of the intrinsic limitations it imposed on ad blockers and security add-ons. Now that it is ready for release, Mountain View will begin phasing out Manifest V2 extensions in Chrome next month.
The massive migration from Manifest V2 to Manifest V3 is about to happen. Starting on June 3, newer Chrome versions in the browser’s three development channels (Beta, Dev, Canary) will begin to see a “warning banner” stating that Manifest V2 extensions will soon no longer work.
Unsupported V2 extensions in the Chrome Web Store will lose their “Featured” badge on the same date. The rollout and discontinuance will accelerate in the coming months, with Google eventually disabling all Manifest V2 extensions. Chrome will direct users to Manifest V3 alternatives in the Chrome store automatically.
The search giant admits that sunsetting Manifest V2 is a significant change for Chrome’s extension ecosystem, so the process will start with stable test builds first. Enterprise organizations using the “ExtensionManifestV2Availability” policy are exempt from the change until June 2025.
Google claims the new Manifest V3 API is more secure than its predecessor. However, many developers have expressed concern that the updated API imposes stricter limitations on security-related extensions. The new framework will essentially force popular add-ons like uBlock Origin (uBO) out of Chrome’s ecosystem, leaving users with much less effective ad-blocking tools.
Developers confirmed (again) that uBlock Origin requires the Manifest V2 API to do its job effectively. The Manifest V3-based “uBlock Origin Lite” extension is far more limited and cannot work like uBlock Origin, regardless of how much they tweak it. Users can expect uBO Manifest V2 for Chrome to work for the next 1 to 3 months before Google breaks it.
Google states that the goal of Manifest V3 has always been clear: to “protect existing functionality” in the browser while improving security, privacy, and performance. The company says that over 85% of “actively maintained” extensions in the Chrome Web Store are running Manifest V3 now, which means that users have many filtering extensions to choose from, including AdBlock, Adblock Plus, uBlock Origin Lite, and AdGuard.
According to uBO developers, the “actively maintained” definition is questionable as many extensions don’t require much maintenance to continue running. Chrome users will likely go through a significant disruption in their browsing experience for the next several months. Meanwhile, Mozilla said Firefox will continue supporting Manifest V2 extensions while implementing the best parts of the Manifest V3 API.
