What Is AIFF?

Apple and Electronic Arts published the AIFF specification in 1988 as a portable audio interchange format for the burgeoning Mac multimedia market — at the time, sound on personal computers was a novel feature. The container is built on EA's IFF (Interchange File Format) chunk-based design, which inspired RIFF (the basis of WAV) at Microsoft a few years later. Two variants exist: AIFF (uncompressed PCM, the form encountered in 99% of cases) and AIFF-C / AIFC (compressed AIFF, supporting μ-law, A-law, IMA ADPCM, and even MACE — virtually obsolete). When Apple's audio stack moved to QuickTime and Core Audio, AIFF stayed as the native uncompressed format throughout the 1990s and 2000s; today GarageBand, Logic Pro, and the macOS afconvert command still produce AIFF when you ask for uncompressed export.

Audio payload: linear PCM, identical to WAV. Byte order: big-endian (Motorola), the only meaningful difference from WAV's little-endian byte order. Channel layouts: mono, stereo, multichannel up to 6 channels in standard AIFF. Supported sample rates: any rate the application writes, but conventionally 8/11.025/22.05/32/44.1/48/88.2/96/176.4/192 kHz. Supported bit depths: 8, 16, 24, 32-bit integer, plus 32 and 64-bit float in newer revisions. Maximum file size: 4 GB (32-bit chunk size field), the same RIFF-era limitation that constrains classic WAV; long sessions need RF64 or AIFF-C with size extensions. ID3 tags are not native; metadata uses AIFF-specific 'NAME', 'AUTH', 'ANNO', and 'COMT' chunks.

Because the payload is uncompressed PCM, AIFF size matches WAV exactly: bitrate equals sample_rate x bit_depth x channels. Worked examples: 44.1 kHz / 16-bit / stereo = 1411 kbps = ~10.1 MB per minute. 48 kHz / 24-bit / stereo = 2304 kbps = ~16.5 MB per minute. 96 kHz / 24-bit / stereo = 4608 kbps = ~33 MB per minute. A 3-minute 16-bit CD-quality AIFF is ~30 MB — large enough to make sharing inconvenient, which is why most users convert to MP3 or AAC for distribution. See [what-is-pcm](/guide/what-is-pcm) for the underlying sampling model.

Sonically, AIFF and WAV are bit-identical when carrying the same PCM payload. The byte-order difference matters only when an application has to read raw bytes without a properly written codec — which in 2026 means almost never. WAV has wider tooling support: nearly every Windows app reads WAV, while AIFF support on Windows is limited to Audacity, VLC, foobar2000, Reaper, and a handful of others. AIFF has marginally better metadata support for some pro audio specifics (loop points for samplers via 'INST' and 'MARK' chunks). Practical rule: deliver WAV unless the recipient explicitly asks for AIFF or you are inside a Logic/GarageBand round-trip workflow. Convert via [AIFF to WAV](/convert/aiff-to-wav).

GarageBand 'Share > Export Song to Disk' offers AIFF as one of three uncompressed options (alongside WAV and Apple Lossless). Logic Pro's bounce dialog defaults to AIFF when 'PCM' is selected. Older Apple sample libraries, third-party Apple-Loops collections, and some film-scoring stem deliveries still ship AIFF. Some hardware samplers (Akai MPC, Elektron Octatrack) accept AIFF natively because the SCSI-era spec settled on AIFF before WAV. Outside Apple ecosystems, AIFF is rare — most cross-platform DAW projects and sound libraries standardise on WAV. See [what-is-aiff-vs-aif](/blog/what-is-aiff-vs-aif) for the .aif vs .aiff extension question.

AIFF-C (sometimes .aifc) is a 1991 extension to AIFF that adds support for codec-stamped chunks: μ-law, A-law, IMA ADPCM, MACE 3:1, MACE 6:1, and (rarely) AAC. The compression ratios were modest by modern standards (4:1 typical) and the codecs are obsolete — IMA ADPCM and MACE were ousted by MP3 within a decade. You will encounter AIFF-C only in legacy Mac archives from the 1990s and in some sampler libraries. Modern Apple software writes AIFF-C only when explicitly requested, and most files claiming to be AIFF-C actually carry uncompressed PCM (the spec allows that). Treat AIFF-C as 'AIFF that might be compressed' and check the codec stamp before assuming.

AIFF to MP3 for sharing: use [AIFF to MP3](/convert/aiff-to-mp3) at 192-256 kbps for transparent quality. AIFF to WAV for cross-platform delivery: lossless re-wrap via [AIFF to WAV](/convert/aiff-to-wav); no quality change, just byte-order conversion. AIFF to FLAC for storage: 40-60% size reduction at zero quality cost — see related [aiff-to-wav-guide](/blog/aiff-to-wav-guide). AIFF to M4A (ALAC) for Apple ecosystem archives: also lossless, smaller than AIFF, supported natively in iTunes/Music. Round trip AIFF → AAC → AIFF: don't — the second AIFF is no longer lossless, even though it claims to be (it carries the lossy-decoded PCM unaltered).