Thank you for making this small but quite effective extension! I used to use YouTube High Definition extension but it stopped working a while ago and not in a continuous maintenance anymore. Before finding this extension, I have tried a dozen of other ones to get a wide screen view in the window mode, but ended with nothing practically useful: they either used JS/CSS tricks (which resulted in a still big blank space at the side with overlapped recommendation sidebar), or required paid subscription for overkill functions. However, this extension just made things work again: a native wide screen in the window mode without interfering with other YouTube components on screen. Great experience!

Fantastic extension. It does what it says, and it does it natively, which means theater mode just happens--no weird resizing glitches to wait for. The app uses the minimal amount of permissions possible. Well done.

work as intended. it just works. thank you so much

my fovorite addon, but no work now(2022/10/22) . please fix it！

Love it, but it no longer works! Please update.

YouTube must have this as toggle setting!

Is it possible to make an extention which makes video on YouTube fullscreen once play button is pressed and back into window once paused?

Does exactly what it says, and doesn't seem to slow down YouTube contrary to what the previous review claims.

Never had a problem with it, it's pretty reliable :)

I just wanted to enable theater mode by default and that's it.

I have never had a problem with the addon, but Avast gave a popup that says that this addon has a bad reputation and recommends I remove it.

You might want to check on that, I couldn't find any information in their forums but I won't be the only one getting that notification.