Audio File Formats

Audio file formats are the different ways digital sound is saved, such as WAV, MP3, AAC, FLAC and Ogg. The format you choose changes two things: how much of the original sound is kept, and how much storage the file needs.

Formats that keep all the sound

WAV is normally uncompressed. It stores every sample exactly as it was recorded, so it gives the highest quality, but the files are very large. A three-minute WAV of the school orchestra rehearsal takes up more than 30 MB, so a whole concert would use a big slice of a phone's storage, and the file takes a long time to send over the internet.

FLAC is lossless compressed: it packs the same sound into a smaller file without throwing anything away, so the quality matches WAV. FLAC is open source, so it does not require licence fees and app developers can add support without paying. However, not all players support it, so a FLAC track you send to a friend might not open on their device.

Lossy formats

MP3 is lossy compressed: it permanently removes the parts of the sound people are least likely to notice. The file becomes small and nearly every device will play it, but some quality is lost.

AAC is a lossy compressed format, and at the same file size it gives better sound quality than MP3. The drawback is that not all players support it, so check compatibility before you distribute a file.

Ogg is a lossy compressed format too, so files stay small, but fewer devices and programs can play it than MP3.