YouTube: Clone/Copy/Move “Watch later” to a new Playlist

Question

I want to clone/copy/move all videos from the "Watch later" playlist to a new one.

Previously the method was to go to this address https://www.youtube.com/playlist?list=WL&advanced_settings=1&disable_polymer=1 clicking the 3-dot-menu and selecting "Add all to".
Currently that URL is redirected to https://www.youtube.com/playlist?list=WL and the 3-dot-menu there does not contain "Add all to" anymore. Other playlists have this option in the menu, but not "Watch later".

My searches come up with even older/simpler methods, but none are current. Seems that this worked until 1/1/21 and even I used it in the past. But now (28/3/21) it seems to be gone.

What is the current method?

Answer 1

I have the exact same question. So far, I haven't found a way to do this that is as convenient as before, but it is possible with this chrome extension...

https://chrome.google.com/webstore/detail/multiselect-for-youtube/gpgbiinpmelaihndlegbgfkmnpofgfei

Unfortunately, it doesn't allow you to add all watch later videos directly to another playlist. However, you can select all of the videos & add them to your queue; then, from the queue, you can save all of the videos to a playlist.

Hopefully, there will be a more straightforward way to do this in the future.