This module is not at all up to date and works very poorly.
Very often it does not detect the video link and returns the following error message :

"An error occurred from remote video site. Please try with other download link."

When you get this then you can choose another format, and if by chance it finds the link the audio is in German !!!!!
There, to understand something, hello anguish.
And since no clear explanation is available I do not know what to do.
I give up on that, there are others that work.
I absolutely want to keep the original language of the video and especially not translate anything because the translation systems are not yet up to date. Maybe in 50 years it will work better ?

Thanks for the great add-on!

Отличное расширение! Качает видео с Ютуба быстро и безотказно, даже очень большие видео, как например записи стримов на несколько часов. Мои самые нежные благодарности разработчикам!

не работает

Tested just now with an age restricted download on youtube and it says An error occurred from remote video site. Please try with other download link.

so needless to say if you can fix that update I'd instantly rate 5. It also doesn't work on private downloader. There's no such thing as terms and conditions on youtube when they are impossible to enforce. Other programs can do it why not this?

Clicking download just brings me to a white screen. Gay.

Не работает

This seems to be the most functional YouTube Downloader extension available right now. The only downside is that instead of starting the download within the page, like you'd expect, it instead opens a new tab for youtube4kdownloader.com to download it from there. However, the download does then start automatically without you needing to do anything, so all you have to do is close the tab after it starts.
I'm no programmer, but it seems like it shouldn't be too difficult to make this download process all happen within the same page/tab. Otherwise, this is great.

The only one that works - tried dozens

Siempre pone que no se puede conectar

Ha ocurrido un error al conectar con youtube4kdownloader.com.

El sitio podría estar no disponible temporalmente o demasiado ocupado. Vuelva a intentarlo en unos momentos.

TRIED THEM ALL. THIS IS THE ONLY FREAKING ONE THAT WORKS!

The user interface of this extension works excellently, but this is of no use if the conversion page is displayed as white as snow. I am using the latest version of Firefox, so this cannot be my fault.

Good, but doesn't downloads shorts.

it does not work well, tried 720p, it took a long time to download, and when played back, the video has sync issues and does not skip well.

it works!!!!

Finally, something that works well!