MP3 vs M4A (AAC): what is the audio codec for portable devices which gives maximum independence? [closed]

A couple of years back MP3 was the most supported format for portable devices. Then Apple came along and wiped the floor of all the portable devices with the iPod as well as the iPhone. They clearly favour M4A (AAC).

When to choose, right now, the 'best' audio codec to encode music to, which would you choose to achieve maximal independence of portable device vendors: MP3 or M4A?

(I am well aware of Ogg (Vorbis): no market (maybe this changes with HTML5 and more WebKit on portable devices), I am also aware of FLAC: I don't want to discuss long term storage.)


If you plan to use your audio files on more than one portable player, especially if you want to use them on future players that you haven't bought yet (so you don't know what formats they will support), MP3 is more or less your only option. Even for players with support for other formats, that support is often incomplete and buggy.

Unless you make sure to only buy Rockbox-compatible players. Then you can use pretty much any format you like.

Of course, the only truly future-proof solution is keeping lossless copies of everything and transcoding to lossy formats for mobile players.


AAC is in very widespread use today. For example, Internet video streams are usually encoded in H.264, and usually uses AAC for its audio. Almost any modern portable media player is able to play back both MP3 and AAC.

However, there are two things to take into account:

  1. AAC is the more efficient codec, meaning that it takes less storage space (=bitrate) for the same audio quality (or the same bitrate for better audio quality). So, from a purely quality-oriented point of view, AAC is plain better and support is widespread enough to give it a go.
  2. AAC is slightly more complex than MP3, which may lead to a slightly higher computational load and hence, slightly decreased battery life especially on older devices. However, higher bitrates generally decrease battery life, too, so this is only a valid argument for MP3 files and AAC files of similar bitrates.

Overall, I would use AAC without hesitation.

(If you want to know more, I posted something about audio quality of MP3s and AAC files a while ago.)