Make youtube video fullscreen using iframe and javascript API

Question

I have an embedded youtube video with hidden controls:

<iframe id="ytplayer" type="text/html" width="400" height="225"
src="http://www.youtube.com/embed/dMH0bHeiRNg?rel=0&controls=0&showinfo=0
&loop=1&hd=1&modestbranding=1&enablejsapi=1&playerapiid=ytplayer"
frameborder="0" allowfullscreen></iframe>

I can control it with the youtube Javascript API.

var tag = document.createElement('script');

tag.src = "//www.youtube.com/iframe_api";
var firstScriptTag = document.getElementsByTagName('script')[0];
firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);

var player;
function onYouTubeIframeAPIReady() {
player = new YT.Player('ytplayer', {
  events: {
    'onReady': onPlayerReady,
    'onStateChange': onPlayerStateChange
  }
});
}

Things like player.playVideo() and so on work perfectly. Now I am looking for a way to make the video play in fullscreen mode with a Javascript call but I couldn't find any method in the API.

Is it even possible (without the controls) and if so - how?

Answer 1

This worked perfect in my case. You can find more details on this link: demo on CodePen

var player, iframe;
var $ = document.querySelector.bind(document);

// init player
function onYouTubeIframeAPIReady() {
  player = new YT.Player('player', {
    height: '200',
    width: '300',
    videoId: 'dQw4w9WgXcQ',
    events: {
      'onReady': onPlayerReady
    }
  });
}

// when ready, wait for clicks
function onPlayerReady(event) {
  var player = event.target;
  iframe = $('#player');
  setupListener(); 
}

function setupListener (){
$('button').addEventListener('click', playFullscreen);
}

function playFullscreen (){
  player.playVideo();//won't work on mobile

  var requestFullScreen = iframe.requestFullScreen || iframe.mozRequestFullScreen || iframe.webkitRequestFullScreen;
  if (requestFullScreen) {
    requestFullScreen.bind(iframe)();
  }
}

Answer 2

I've added code to do fullscreen (real full screen, not full window) to my answer on Auto-Full Screen for a Youtube embed.

YouTube don't expose fullscreen in their API, but you can call the native browser requestFullScreen() function from the playerStateChange() event from the YouTube API or make your own custom play button like I have.