AIFF vs AU
A detailed comparison of AIFF Audio and Sun AU Audio — file size, quality, compatibility, and which format to choose for your workflow.
AIFF Audio
Audio FilesAIFF is Apple's uncompressed audio format, equivalent to WAV in the macOS ecosystem. It stores CD-quality PCM audio and is widely used in professional audio production on Apple hardware.
About AIFF filesSun AU Audio
Audio FilesAU is a simple audio format from Sun Microsystems, commonly used on Unix systems.
About AU filesStrengths Comparison
AIFF Strengths
- Lossless and uncompressed — bit-exact audio reproduction.
- Native to macOS and all Apple Pro Audio apps.
- Simple structure — trivially parsed by audio libraries.
- Supports up to 32-bit float, 192 kHz, and multi-channel audio.
- Rich metadata via named chunks (annotations, markers, MIDI).
AU Strengths
- Trivially simple format — 24-byte header, then samples.
- µ-law 8-bit variant fits hours of speech in kilobytes.
- Stable since 1988; every major audio library reads it.
- Streaming-friendly: size field is optional.
Limitations
AIFF Limitations
- Enormous file sizes — 10 MB per minute at CD quality.
- No built-in compression — use FLAC for lossless with smaller files.
- Big-endian byte order confuses tools written on little-endian hardware.
- Less common on Windows; WAV is the local equivalent.
AU Limitations
- Aging — obsolete outside legacy and compatibility scenarios.
- No metadata beyond a single annotation string.
- No native multi-channel surround support.
- Limited to 8 codecs, none modern.
Technical Specifications
| Specification | AIFF | AU |
|---|---|---|
| MIME types | audio/aiff, audio/x-aiff | audio/basic, audio/au, audio/x-au |
| Extensions | .aif, .aiff, .aifc | .au, .snd |
| Byte order | Big-endian | Big-endian |
| Max bit depth | 32 bits (PCM or float) | — |
| Max sample rate | 192 kHz (practical); unlimited (spec) | — |
| Header | — | 24 bytes (magic, offset, size, encoding, rate, channels, info) |
| Codecs | — | PCM 8/16/24/32-bit, µ-law, A-law, IEEE float |
Typical File Sizes
AIFF
- 3-min song (CD quality) 30 MB
- 3-min song (24-bit / 96 kHz) 100 MB
- Full album (CD, 10 tracks) 450 MB
AU
- 10-second clip (8-bit µ-law, 8 kHz) 80 KB
- 10-second clip (16-bit PCM, 44.1 kHz stereo) ~1.7 MB
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Frequently Asked Questions
AIFF (AIFF Audio) is an audio file format used to store sound recordings — music, voice, podcasts, sound effects. The format defines how the audio samples are compressed (or stored raw), what bitrates are supported, and how metadata such as title, artist, album, and cover art is embedded. It is part of the audio files family.
AIFF (AIFF Audio) is an audio formatoo de arquivo used to store sound recordings — music, voice, podcasts, sound effects. The formato defines how the audio samples are comprimido (or stored raw), what bitrates are suportado, e how metadata como title, artist, album, e cover art is embedded. It is part of the audio arquivos family.
VLC, foobar2000, and the default media players on Windows and macOS handle AIFF natively. On mobile, iOS Music and Android media apps vary in their support — popular formats work everywhere; niche ones may need a dedicated app. If playback fails on a device, converting to MP3 or AAC usually solves it.
VLC, foobar2000, e the default media players no Windows e macOS handle AIFF natively. On mobile, iOS Music e Android media apps vary in their support — popular formatoos funcionar everywhere; niche ones may need a dedicated app. If playback fails em um device, convertendo to MP3 ou AAC Geralmente solves it.
Upload the AIFF to KaijuConverter and pick MP3, WAV, FLAC, AAC, OGG, or any other target. Our FFmpeg pipeline decodes the audio and re-encodes to the target format at sensible default bitrates (VBR ~190 kbps for music, 96 kbps for speech). Metadata and cover art travel with the audio where both formats support them.
AIFF can be lossy or lossless depending on the specific variant. Lossy variants (smaller files) discard some audio detail during compression in ways tuned to be inaudible; lossless variants preserve every sample exactly but produce larger files. For distribution, lossy at high bitrate is standard; for archival, lossless wins.