Detecting if a browser is in full screen mode

Question

Is there any way of reliably detecting if a browser is running in full screen mode? I\'m pretty sure there isn\'t any browser API I can query, but has anyone worked it out b

Answer 1

The Document read-only property returns the Element that is currently being presented in full-screen mode in this document, or null if full-screen mode is not currently in use.

if(document.fullscreenElement){
  console.log("Fullscreen");
}else{
  console.log("Not Fullscreen");
};

Supports in all major browsers.