Firefox Picture-in-Picture

All browsers support it at this point, it's super nice. What Firefox got right is they display the button over every video, while other browsers require a right-click (which just about every video hosting site overrides).

I've had this bookmarklet for a while:

javascript:document.querySelector('video').requestPictureInPicture();

In Chrome / the new Edge, you can add that as a bookmark named PIP or whatever you want. Now when you go to a video on GB or YouTube, type "pip" into your address bar, and wham, PIP everywhere.

Edit: In Safari, the bookmarklet would be different. But you don't need it as much there, since you can right-click the volume icon and access PIP from there:

Chrome has a built in Picture in Picture extension that works quite well although it leaves a blank tab

Also it only allows for one video to pop-out so you can't have like 3 popped out videos playing at once - not sure if this is a common limitation or just for Chrome.

https://chrome.google.com/webstore/detail/picture-in-picture-extens/hkgfoiooedgoejojocmhlaklaeopbecg?hl=en

I have been looking for this information for a long time, I was very surprised when I found it here.