Playing YouTube in the background might not sound like something very important to know how to do, until you actually need it some day. Unless you’re interested in using third party apps to be able in play YouTube in the background, here’s how you can do it in Chrome on you Android Smartphone.
1) In Chrome, go to YouTube. Play the video you want to run in the background.
2) Not tap on the tree dot menu and tap on “Request desktop site”.
3) Play the video, and you can safely navigate away from Chrome. The sound might stop, in which case you can simply resume the video from the Notification Shade,
So, not only you not require a third party app to be able to play YouTube in the background, you even get the ability to play or pause the video directly from the notification shade itself.