The latest version of Google Chrome makes picture-in-picture mode a default feature in the web browser. As we already know what picture-in-picture mode does, it keeps videos in a floating window that’ll follow you around as you browse or even as you open another program. A few conditions though, the developers need to support it and you’ll need to keep the original tab open so the video keeps running. But once you updated your browser to Chrome 70, you just need to head over to YouTube and when you start playing a video right click on the video twice until the Chrome dropdown menu shows up. You can just select Picture in Picture option from there and then you’re good to go. 

Source: Engadget