File Formats for Music

Have you ever wondered about the different file formats for music? Here’s a short primer.

AIFF files are encoded at 1411 Kbps. It is uncompressed but unlike WAV, it supports album artwork and more tags. With artwork and tags, AIFF can require more storage than WAV. A 3:30 minute recording without artwork is 36.9MB.

WAV files are lossless, no compression, and therefore have very high storage requirements. The recording is encoded at 44,100 Hz, and the sample size can be either 16-bits (standard for CDs), 24-bits, or 32-bits, the latter being twice as large at the standard. A 3:30 minute recording at 16-bits is 36.9MB. The same recording at 32-bits is 73.8MB.

MP3 files are encoded at 320 Kbps. It is compressed with decent quality. MP3 is the most popular format. A 3:30 minute recording at standard compression (170-210kbps) is 3.4MB. A 3:30 minute recording at low compression (320kbps) is 8.4MB.

AAC (aka M4A) is similar to MP3 but is a bit more efficient (files are slightly smaller than the lowest compression MP3). Apple iTunes has made this a popular format. A 3:30 minute recording is 7.2MB.

To complicate things, WAV files can be compressed with the MP3 format.

Other file formats are OGG (Vorbis), FLAC, WMA, WMA Lossless, and Opus. The FLAC format can compress from 50% to 70% and quickly decompress back to the original. It is becoming a popular option as it is considered to be a lossless format with high compression.

All file sizes above were derived by using Audacity to export from an AIFF file to the other formats. The AIFF file was copied directly from a CD.

Regardless of the file format, when a file is included in iTunes, iTunes can add artwork and more tags to the file.

John R Carter, Sr.