Firefox MV3 stands apart from other iterations of MV3 in two critical ways: We want to give extension developers creative flexibility and choice, while ensuring users maintain access to the highest standards of extension customization and security. That said, we’re also implementing distinct elements to suit Firefox’s product and community needs. As we continue to collaborate with other browser vendors and the developer community to shape MV3, we recognize cross-browser compatibility as a fundamental consideration. Mozilla’s vision for Firefox MV3įirefox MV3 offers simplified and consolidated APIs, enhanced security and privacy mechanisms, and functionality to better support mobile platforms. For now, please see this guide for supporting both MV2 and MV3 versions of your extension on AMO. Once this timeframe is established, we’ll communicate MV2’s closure process with advance notice. Towards the end of 2023 - once we’ve had time to evaluate and assess MV3’s rollout (including identifying important MV2 use cases that will persist into MV3) - we’ll decide on an appropriate timeframe to deprecate MV2. In these instances, we intend to take the time necessary to make informed decisions about our approach. Taking a gradual approach and gathering feedback as MV3 matures, we anticipate opportunities will emerge over time to modify our initial MV3 offering. Our goal has been to ensure a seamless transition from MV2 to MV3 for extension developers. To be clear, Firefox will continue to support MV2 extensions for the foreseeable future, even as we welcome MV3 extensions in the release to general availability in Firefox 109 (January 17, 2023). Getting an early jump on MV3 signing enables you to begin testing your extension’s future functionality on Nightly to ensure a smooth eventual transition to MV3 in Firefox.

Starting Novemadd-on developers are welcome to upload their Firefox Manifest version 3 (MV3) compatible extensions to (AMO) and have them signed as MV3 extensions.

Mozilla firefox 48 version