The format typically used for compressing audio files is MP3 (MPEG Audio Layer III). MP3 is a lossy compression format that reduces the size of audio files while preserving acceptable sound quality for most listeners. Its efficiency in maintaining audio fidelity at lower bit rates has made MP3 a popular choice for digital music distribution, streaming services, and personal music collections. Additionally, MP3's widespread compatibility with various devices and platforms has established it as a standard format for audio playback and sharing.