What Audio File Types Can the iPhone Play?

The iPhone supports many popular audio file formats

Teenager listening to music on iPhone against wall with graffiti
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There is a misconception that the iPhone only supports the AAC format and can only play audio purchased at the iTunes Store. In fact, the iPhone supports many different audio formats. Whether you are using a current iPhone or turning an older iPhone into the equivalent of an iPod touch, you end up with a powerful music player.

So What Caused the Confusion?

It is true that any music you download to your iPhone from iTunes is in the Advanced Audio Coding (AAC) format. It isn't the AAC format you might find elsewhere, though; it is a protected or purchased version of AAC. However, you may have music in iTunes that came from other sources, and that music is most likely to be an MP3 or another format. iTunes can play your MP3s and other formats just fine. So, if you rip a CD to your computer or buy music online in other formats, you can play it on your iPhone, as long as it is in one of the formats that iOS supports on Apple's mobile devices.

iPhone Audio Format Specifications

Learning about the audio formats that the iPhone supports is important if you want to start using your iPhone as a portable media player. It matters when the contents of your music collection come from different sources — like a mix of online music services and ripped CD tracks, digitized cassette tapes, or vinyl records, all of which are legal to copy into iTunes if you own the original recording. If this is the case, there's a good chance you have a mix of audio formats. 

Supported audio formats are:

  • AAC-LC: ACC Low Complexity is a lossy audio format optimized for streaming audio and low-bitrate applications.
  • HE-ACC and HE-ACC v2: Both High-Efficiency Advanced Audio Coding versions are lossy compression formats good for software media players, streaming music, and internet radio. V2 has a few more features than the original version. HE-ACC files are also called MPEG-4 ACC files.
  • ACC Protected: All songs sold on iTunes before 2009 are in ACC-protected format, a lossy format that includes Digital Right Management (DRM). You can't burn these to CDs.
  • ACC Purchased: All songs sold on iTunes after 2009 in iTunes + format do not include DRM. The format is lossy.
  • Apple Lossless: This lossless format delivers no quality loss of music tracks at all. It is similar to the FLAC format.
  • FLAC: This Free Lossless Audio Codec format provides lossless compression of digital audio. When FLAC files are decompressed, the audio is identical to the original.
  • Linear PCM: This audio data format is often used on audio CDs. The data is not compressed, so the files are large, but the quality is good.
  • MP3: MP3 is a lossy audio format and the most popular of the audio types used for digital music.
  • Dolby Digital (AC-3): Dolby Digital is a lossy audio compression format that carries up to six channels of music.
  • Dolby Digital Plus (E-AC-3): Dolby Digital Plus is an enhanced version of Dolby Digital that offers increased bitrates and support for more audio channels.
  • Audible formats 2, 3, and 4: Developed by Audible, the spoken word company, lossy format 2 delivers 8 kbps of sound, on a par with AM radio. Format 3 at 16 kbps delivers sound equal to that of an FM radio, and format 4, with a bitrate 32 kbps, has sound quality comparable to an MP3.  
  • Audible Enhanced Audio (extensions AAX and AAX+): Enhanced Audio formats at 64 kbps are deemed to have CD-quality sound. These uncompressed files deliver a sound that is superior to Audible formats 2, 3, and 4. They are larger files than those of the lossy formats.

Not all of these formats are used with music, but they are all supported by the iPhone in one place or another.

Difference Between Lossy and Lossless Compression Formats

Lossy compression removes information from the pauses and blank spaces in an audio recording, which makes lossy files much smaller than lossless or uncompressed files. However, if you are an audiophile and buy high-resolution music online, you aren't going to want to convert it to a lossy format. For most listeners, lossy works just fine, and when you store music on your iPhone, rather than stream it, size matters.

How to Convert Music From Unsupported Formats

If you have music in a format that iTunes doesn't support, iTunes on a computer converts it to an audio file that is compatible when it imports it. By default, iTunes converts incoming files using the ACC format, but you can change the format in iTunes Preferences > General > Import Settings. Your choices affect the quality of the audio and the size of the audio file. For example, if you prefer to listen to audiophile-quality music, change the default to Apple Lossless Encoder. These settings aren't available for iTunes on the iPhone, but you could change your preferences in iTunes on the computer and then sync the music to the iPhone.

Uses for the iPhone and Digital Music

As well as being a great smartphone, there's a lot you can do with the iPhone when it comes to listening to audio files. For starters, the iPhone makes a stellar portable media player that plays audio, videos, podcasts, and audible books. You may have already synced the iPhone with your iTunes music library or with your music on iCloud and listened to your songs on the go. The iPhone can also be used to access Apple's streaming music subscription service Apple Music, while apps like Spotify and Pandora supply an almost unlimited supply of music.