Get your own website Result Size: 625 x 565
x
 
<!DOCTYPE html>
<html>
<body onresize="myFunction()">
<p>Try to resize the browser window to display the windows height and width.</p>
<p id="demo"></p>
<script>
function myFunction() {
  let w = window.outerWidth;
  let h = window.outerHeight;
  let txt = "Window size: width=" + w + ", height=" + h;
  document.getElementById("demo").innerHTML = txt;
}
</script>
</body>
</html>