4k Video Downloader - 4K Video Downloader is a software program that helps people download video files from sites such as Facebook, YouTube and Dailymotion.
CONV. - Convert YouTube video to MP3, GIF or MP4
yt2mp3.org - Free online YouTube to MP3 Converter
Downie - Video download for OS X. Downie supports at this moment over 1,000 different sites.
DVDVideoSoft YouTube to MP3 Converter - Best YouTube to MP3 Converter of 2019. Any format, any quality, ad-free. Easy YouTube playlists downloads. Loved by users since 2006.
Yout - YouTube to Mp3 Converter