safari-web-extension-converter not working with manifest_version 3

I have a very basic extension with manifest_version: 3 I tried to convert it through safari-web-extension-converter but it failed to convert with the error unable to parse the manifest.json.

I changed the version to 2 and it worked perfectly.

Is there no compatibility for manifest version 3 extension conversion?

I checked the Assessing Your Safari Web Extension’s Browser Compatibility article, but it had no mentions regarding the manifest version 3 incompatibility.

Is there something else, that I could be missing? and is this documented somewhere else?

My system info:

macOS 11.4 Big Sur

XCode 13.0 beta 3



Hi there,

I am the developer of the Turn Off the Lights browser extension (Safari extension), and you can only write with manifest version 2 for all platfoms. That includes the Safari web browser. And Manifest v3 is only now available in Google Chrome (stable).

And Apple will not discuss here the further plan to support Manifest version 3. However, they did announce that they joined the W3 Browser Extension Community Group for browser extensions. All web browsers are in the same group to standardize the browser extension platform (Google, Microsoft, Firefox, and Apple).

Thanks, Stefan