Overall Findings
AAC and MP3 are the most common file types used with the iPhone and iTunes. They’re similar, but they differ in four important ways.
File Size: AAC for the Win
Both AAC and MP3 are compressed file formats. That means that they make files small by removing some hard-to-hear parts of the song while keeping the sound quality good. AAC is generally the slightly smaller file type. AAC files are generally higher quality and slightly smaller than MP3 files of the same song. The reasons are technical, but the simplest explanation is that AAC was created after MP3 and offers a more efficient compression scheme so that less audio quality is lost.
Compatibility: MP3 Works Just About Everywhere
MP3 is the most common digital music format, so you can count on virtually any device being able to play it. AAC isn’t as common, but most devices can play it, including all Apple products. AAC was not created by Apple and it’s not a proprietary Apple format. AAC can be used with a variety of non-Apple devices, although it is the natural file format for the iTunes Store and Apple Music.
Audio Quality: The Sweet Sounds of AAC
How good the music sounds in each file format is key. It can be tough to distinguish between AAC and MP3 files on most devices, but AAC sometimes sounds slightly better.
Proprietary Format: It’s a Toss-Up
Digital Rights Management (DRM) refers to restrictions on how you use and share your music. There’s no DRM restriction on files you create, but if you buy music from a store or download music from a streaming service like Apple Music, it’s worth finding out if DRM is used.
Final Verdict: AAC
If you plan to stick with the iPhone, iTunes, and Apple for a long time, use AAC for your digital music. You can always use iTunes to convert AAC files to MP3 format if you decide to switch to a device that doesn’t support AAC (though there aren’t many such devices). In the meantime, using AAC means that your music will sound good and you’ll be able to store a lot of it.
