W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<body>

<p>Click the buttons to create a VIDEO element, one with preload set to "none", and one with preload set to "auto".</p>

<button onclick="myFunction('none')">Video without preload</button>
<button onclick="myFunction('auto')">Video with preload</button>
<br>

// Set the preload property:
  x.preload = p;

document.body.appendChild(x);
}
</script>

<p><b>Note:</b> The preload attribute is not supported in IE.</p>

</body>

</html>

​x
 
<!DOCTYPE html><html><body>​<p>Click the buttons to create a VIDEO element, one with preload set to "none", and one with preload set to "auto".</p>​<button onclick="myFunction('none')">Video without preload</button><button onclick="myFunction('auto')">Video with preload</button><br>​<script>function myFunction(p) {  var x = document.createElement("VIDEO");  x.setAttribute("controls", "controls");  var y = document.createElement("SOURCE");  y.setAttribute("src", "movie.mp4");  y.setAttribute("type", "video/mp4");  x.appendChild(y);  var z = document.createElement("SOURCE");  z.setAttribute("src", "movie.ogg");  z.setAttribute("type", "video/ogg");  x.appendChild(z);​  // Set the preload property:  x.preload = p;​  document.body.appendChild(x);}</script>​<p><b>Note:</b> The preload attribute is not supported in IE.</p>​</body>​<!-- Mirrored from www.w3schools.com/jsref/tryit.asp?filename=tryjsref_video_preload2 by HTTrack Website Copier/3.x [XR&CO'2014], Wed, 21 Dec 2022 18:17:03 GMT --></html>​