It is not working when open video in new table.

It does not work...

This one kills the YouTube channel home page entirely.

It works but it disables (breaks) my Youtube STOP button Add-on!

Не работает, не останавливает видео. Not work, autoplay still work

FINALLY! AN ADON THAT DOES WHAT IT'S SUPPOSED TO DO! THE USERS WILL TAKE THEIR WEB EXPERIENCE BACK FROM THESE WACK JOBS!

Работает, в отличии от других. По крайней мере на ютубе авто воспроизведение отключает.

Doesn't perform well enough for initial page load. There will be a brief second or two that the video would still play before it gets replaced by a non-playing video.

Just works.

None of the Youtube extensions have this functionality anymore, but the good news is this works perfectly alongside Enhancer and other extensions [atm].

Thank you very much!

This does not work on Firefox portable 63.0.3 (64-bit) on my computer. In the reviews of this app I found the best answer written by thomas glico. Editing about:config - media.autoplay.default 1 works perfectly.

Great idea with the menu and all... but it does not work. YouTube playlist keeps playing next videos.

the best solution :
https://support.mozilla.org/fr/questions/1238091
in about:config you can set media.autoplay.default to 1 in order to block automatic playback on all pages or set it to 2 to decide on a per domain basis.

Simply, functionally - The Best! Thanks!

I appreciate the effort that it takes to write plugins so no hating here, just comment on why this wasn't a solution for me. Firstly, as others have said, it takes a while to kick in. It plays a few seconds of the video before it is stopped. This is annoying (mostly for my neighbors). Secondly, the stopping pre-load feature effectively means that one has to click twice to start the video, once to stop pre-load and once to start the video. I used the suggestion that itge13 made in one of the comments (the simple change to the config file) and it works well, so I uninstalled this plugin. It needs a bit more work but on the other hand, the about:config method is quick, easy and works (in Firefox at least) so I see no point in further development.