Who hasn’t ever wanted to download audio in mp3 format from YouTube? I think most of us. Having many applications that help us with this, the developers of Mozilla Firefox plugins bothered to give us a simpler alternative.
YouTube to MP3 is an extension that integrates an audio download link just below the embed code, this link brings us to Video2mp3, a service that allows us to download the audio in mp3 format.
Link | YouTube2MP3
Source | Punto Geek