Audio File Formats Compared
The common audio file formats side by side — lossless vs lossy, rough file size, and what each is best used for. WAV, AIFF, FLAC, ALAC, MP3, AAC, Ogg Vorbis and Opus.
| Format | Ext | Compression | Size | Best for |
|---|---|---|---|---|
| WAVUncompressed PCM | .wav | Lossless | Very large | The studio interchange standard; universal. |
| AIFFUncompressed PCM (Apple) | .aiff | Lossless | Very large | Apple's WAV equivalent. |
| FLACFree Lossless Audio Codec | .flac | Lossless (compressed) | ~50–60% of WAV | Archiving and hi-fi distribution; open. |
| ALACApple Lossless | .m4a | Lossless (compressed) | ~50–60% of WAV | Lossless inside the Apple ecosystem. |
| MP3MPEG-1 Audio Layer III | .mp3 | Lossy | Small | Universal compatibility; legacy default. |
| AACAdvanced Audio Coding | .m4a | Lossy | Small (better than MP3) | Streaming, YouTube, Apple Music. |
| Ogg VorbisVorbis in an Ogg container | .ogg | Lossy (open) | Small | Open-source; common in games. |
| OpusIETF Opus | .opus | Lossy (open) | Smallest at low bitrate | Voice, streaming, WebRTC, Discord. |
"Lossless" keeps every bit of the original; "lossy" discards inaudible detail for much smaller files. Estimate uncompressed sizes with the audio file size calculator.