Detect fullscreen mode

Question

Modern desktop version of IE 10 is always fullscreen.

There is a living specification for :fullscreen pseudo-class on W3

But when I tried to det

Answer 1

Here is the most up to date answer. fully browser compatible with all the prefixes:

function IsFullScreen() {
     return !!(document.fullscreenElement || document.mozFullScreenElement || document.webkitFullscreenElement || document.msFullscreenElement)
}

credit to https://developers.google.com/web/fundamentals/native-hardware/fullscreen/

DEMO

function IsFullScreen() {
  console.log(!!(document.fullscreenElement || document.mozFullScreenElement || document.webkitFullscreenElement || document.msFullscreenElement))
}

log fullscreen state