Don't work.

Buggy. Doesn't let me refresh https://www.youtube.com/feed/subscriptions

I was using media.autoplay.enabled flag in about:config to autostop HTML5 videos which works great.
BUT... it broke a lot of sites like Hulu, Spotify, etc.
This is great. Now I can autoblock HTML5 autoplay and still whitelist sites.
Thank you, this add-on saved my sanity.

This blocks a lot of videos, and even entire channel pages, from loading in YouTube. Even if you tell it to not block anything on the page you are on, it still prevents them from loading. I am disabling this addon for now, I will remove it entirely if it isn't updated in a timely manner to not do this in FF 57.

it's a stupid addon,if you let it on,it stop the player when you click the play button over and over

Seems to work for me...it does break some websites--but so does the built-in FIrefox preference in about:config. This at least lets you whitelist sites that break...

Really this addon shouldn't be necessary--Mozilla should add click-to-play html5 video built-in, like they have for Flash...

Fait bugger beaucoup de choses, à commencer par les vidéos elles-même et rends les userScripts (via GreaseMonkey) totalement inutilisables.

Doesn't seem to prevent autoplay at most sites. Not even at big sites like Youtube - you'd think that it would be the first place to test an add-on like this, but oh well.

Can't play videos at all with the add-on enabled now.

BLOCK TWITCH FROM AUTOPLAY VIDEO BUT THEN I CANT START THEM...

it doesnt do anything at all

Twitch being the worst affected. Video doesn't load at all when it's not whitelisted.

Do the job on some website (not all), but breaks some others too, and sometime adblocks.

I've had a few websites break with this enabled.

As of a week ago (8th September) it doesn't seem to work with YouTube videos any more. It is a real shame as I've found the add-on to be very useful, and I hope this issue can be fixed quickly. Come on, dev, we know you can do this! ;·)

doesn't always work on youtube

Ttffy

Can`t play youtubes video. It even block play button!

You deserve some sort of medal for getting cnn.com to STFU.

No, seriously, they try to load and play their videos in at least a half dozen ways ....