The following will show you another one — YouTubeMP3.tv, which is also free for you to convert YouTube videos to MP3 online with 3 obvious advantages:
1. You can search YouTube videos
Besides to insert a YouTube video URL like many other converters, you can also enter any keywords and search for a YouTube video to convert and download.
2. You can control the conversion quality and time
For every YouTube video, you can convert it to MP3 in normal or high quality.
And for every video in the search results, you can click on the "Advanced Download" button below it to record any section in Low, Medium, High or Very High quality, and you can even edit the ID3 tags of the video.
3. You can convert videos from the YouTube website directly
For Chrome or Firefox users, you can install the YouTubeMP3.tv extension and start to convert videos to MP3 from the YouTube website directly.
But, the color of the extension buttons is black, they will be invisible if the background color of the YouTube video page is black, as what you can see from the above screenshot.
By the way, if you want to convert YouTube videos to MP4, FLV, MP3 and/or some other format files, you can check out these 10 websites.