My options were MP3 or MP4 only-neither worked. First message was "One Moment please, Preparing your download links!" then "Error: No Streams found!" every time.

good

Nova aba para converção. Que droga

Beware of this addon. Once you insert the youtube web address you want converted, the addon pops up requesting to add other programs and services. Do you really know what they are downloading? That's not all, if you try to restart the conversion, they begin to ask you for permission to send notifications. Not one or two but numerous. For this reason, I have deleted the Mp3Converter.net. Strongly consider the risk before adding this addon.