MediaHuman YouTube To MP3 Converter Extracts MP3 audio from YouTube, Vimeo, Dailymotion and SoundCloud.

Youtube Video and Audio Downloader is an open-source project, downloading Youtube videos.

Easy Youtube Video Downloader is a cross-browser, cross-platform and free web-browser add-on to perform conversion on external servers.

FLVto is a youtube to mp3 converter website.

ClipGrab is a multi-platform software for downloading videos from popular websites such as YouTube, Vimeo, Dailymotion or Metacafe.

Airy helps to download videos from YouTube in different format types and resolutions for Mac and Windows.

4K YouTube to MP3 was specifically created to extract audio from YouTube, Vimeo or Facebook and save it in MP3, M4A, OGG.