Manifest version 3 is not supported for Firefox extensions

Why manifest version 3 is not supported for Firefox extensions? So I can just publish chromium extension.

Mozilla is working on it. But it is much more than just a manifest.json file. Don’t know what ETA is, but this is a meta tracker bug:

Doesn’t Google still accept manifest v. 2 submissions?

I mean only thing they need to do is accept manifest_version: 3 and they would need to replace page_action (Which is v2) to action (Which is v3) so only 2 changes and 80+% extensions would work out of the box.

On Opera extension on v3 manifest works. But when I try to upload it to their extension store it says that manifest v3 is not supported even tho on Opera extensions with v3 manifest works amazing.

I have also tried changing manifest to v2 but it didn’t work in Opera. So only manifest v3 works on all chromium based browsers.

I’m not sure if I understand which browsers you can get v2 and v3 to work on or not. And why…

But regarding Firefox, this was posted on Mozilla Add-ons Blog today:

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Thanks again. Today I have also manage to convert the whole project to support Manifest v2 so FireFox would be supported too, but was this even worth it if they will soon add support to v3?

@zigazajc007 We’re still a couple of months away from developers even being able to test manifest v3, much less submit v3 versions. :slight_smile: You can wait if you would like but if you want to get the extension to Firefox users sometime soon you may want to convert.

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I use Mozilla Firefox (115.5.0) and when I try to upload extension with ‘“manifest_version”: 3’, extension is loaded, but does not work, and when change to M_V: 2, it is loaded and working as it should why?

It may be best to start a new thread instead.
Also, note that Firefox doesn’t support service workers yet, so you need to change your manifest file a bit, more info here:

You can also simply keep using MV2, there is no deadline for MV3 migration in Firefox.