Firefox compatibility with Manifest V3 #2
Description
At the time of creating this ticket, Firefox still uses V2 manifest, solely. They mentioned they would support V3 as well, with some differences - https://blog.mozilla.org/addons/2021/05/27/manifest-v3-update/.
Latest update: https://blog.mozilla.org/addons/2022/05/18/manifest-v3-in-firefox-recap-next-steps/
MV2 and MV3 timelines:
Firefox
The expected timeline for V3 support to appear is 2021 Q4 or 2022 Q1.
It seems they would continue the support for V2 at least year after V3 becomes available.
Chrome
(from: https://developer.chrome.com/docs/extensions/mv3/mv2-sunset/)
One of the bigger differences between V2 and V3 is moving away from the concept of "background scripts" towards using service workers. Here the post detailing differences and a guide for migrations - https://developer.chrome.com/docs/extensions/mv3/migrating_to_service_workers/. This is not a change entirely for the better (as far as developers are concerned), so some partial support for background pages might happen as well.