MP3 is by far the most common format for audio files nowadays. However, there are times when you need to convert MP3 into another format on your Mac. Whether it's because you can't play files in MP3 format for some reason, or you want to play MP3 files in another format on your mobile device, here are 5 top free apps on the Mac to do so:

ffmpegX is probably the fastest and most flexible video and audio encoder for Mac. It can convert just about anything and also includes a rather basic but handy media player so you can preview your newly converted audio. If you delve into the settings you'll see you can perform all sorts of advanced functions like joining, fixing or authoring audio as well as set bitrate.

HandBrake is another hugely popular video and audio converter and includes a very handy bitrate calculator so that you can control the quality of your converted MP3s. It's mainly used for video conversions but it's just as suitable for audio including MP3. The only drawback you might find is that it can be a bit slow.

Switch has the advantage of being dedicated to audio conversions and allows you to quickly batch convert audio tracks. It has a huge number of output formats including MP3, WMA and AAC. You can also set the bitrate and there's also a handy "error protection" feature which ensures conversions are error free.

All2MP3 is dedicated specifically to MP3 conversions and uses AppleScript to perform fast and efficient conversions. It's easy to use thanks to a simple drag and drop interface and all you have to do is click on the All2MP3 button to start converting. The program converts conversion from MP3 to MPC, APE, WV, FLAC, OGG, WMA, AIFF and WAV.

Kigo Video Converter is designed mainly for video conversion but is also suitable for MP3 needs. It's especially designed with the needs of iPods, iPhones, Archos and other major portable audio devices in mind. The pre-defined settings for each device are one of the stand-out features of Kigo Video Converter because it saves so much hassle setting bitrates.