Google Chrome 88 introduced the Manifest V3 API for extensions, which not only significantly changes how some extensions work, but also will be mandatory soon. Google has now shared an updated timeline for the switch.
Manifest V3 is the new software platform for Chrome extensions, intended to make extensions faster and more secure. The change has been controversial due to Google’s removal of the webRequest API, which is used by content blocker extensions to filter out network traffic. The API was replaced with declarativeNetRequests, which has an upper limit on the amount of rules (around 30,000 right now). Many content blockers have hundreds of thousands of rules, which is why the popular uBlock Origin extension is currently being reworked to meet Google’s requirements, while the V3-compatible version of AdGuard doesn’t support the same filtering rules as before. The new limitations on background tasks will also make some extensions less useful, or break them entirely.
Google already stopped accepting new Manifest V2 extensions in January 2022, and now the company has shared a more specific timeline on the transition to V3. Starting in January 2023, with the release of Chrome 112, Google will start testing experiments that turn off all Manifest V2 extensions in the Canary, Dev, and Beta channels. Later in June 2023, the Chrome Web Store will unpublish all V2 extensions, and Chrome will start experimenting with turning off V2 extensions in the stable channel. Finally, in January 2024, all Manifest V2 extensions will be fully removed from the Chrome Web Store.
Google is still working on improvements to Manifest V3 to address developer complaints, including support for userscript extensions (like Tampermonkey), increased storage, and restoring the ability for extensions to create background pages for some tasks. Still, some of the improvements won’t be ready until close to the shutdown date for Manifest V2, which doesn’t leave developers much time to test and release updates.
Other browsers that support Chrome extensions are also working on Manifest V3 support, but some of them are leaving the webRequest API in place. Safari 15.4 added Manifest V3, and Firefox is working on it.
Source: Chrome Blog