We always meet MKV files in our daily life. Though MKV format is more common than it used to be, some old-fashioned media players still cannot support it. The necessity to convert MKV to MP3 arises when you need MP3 files from MKV videos to create a song list, save audio tracks, use as background music, etc. Under these circumstances, a professional video converter could make the process much easier. This article is about to introduce you 3 most simple and easy-to-use tools to help you do that on Windows and Mac instantly and perfectly.