At MDN you have a browser compatibility chart for each API entry documented at the end of the page describing and there is also this page here: https://develop

At MDN you have a browser compatibility chart for each API entry documented at the end of the page describing and there is also this page here: https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Browser_support_for_JavaScript_APIs https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Br...