Use Openshot (free) to combine the audio and video files. I wish a developer would update this. ffmpeg needs a different command line. This used to work and was fast, some years back

ΔΕΝ δουλεύει...!!! :((

As of the most recent YouTube UI Update (Thx Google), this addon no longer works. The download button doesn't appear anywhere below or around the YT video.

Unknown if the addon author will update, but use something else until they choose to update it.

Used to be an excellent app. Since about a year now, it doesn't combine video with audio anymore despite a few attempt to uninstall and reinstall. Really unfortunate.

Works as a charm

vraiment simple et performant

Demasiado lento y por tanto inútil... aunque coge rápido el enlace, las descargas no pasan de 50 Kb/s...
Y después de un año de uso, no ha mejorado nada.¿De qué sirve que la extensión conecte los enlaces enseguida si después tarda una eternidad en descargarlos?

This used to be the best add-on for downloading any video from youtube. It took a while to download, but there was nothing wrong with the video in the end, and it had no watermark or QR code or the like. But for months now it has not worked. At best, it will download the audio and video files, but it will not combine the two to give you the video you wanted to download from youtube. In short, this add-on does absolutely nothing now.