AIFF vs FLAC: Which Lossless Format Is Better?

Both AIFF and FLAC are lossless. Decode either one and you get the exact same audio as the source. So why do both exist, and which should you use?

Audio Quality

Identical. Both are lossless. The decoded audio from AIFF and FLAC is bit-for-bit identical to the source. There is no quality difference between them. Anyone claiming AIFF sounds warmer or more natural is experiencing a placebo effect.

This point is important: choose based on features and compatibility, not audio quality. Quality is the one thing that is not a differentiator here.

File Size

AIFF wins on simplicity; FLAC wins on size. AIFF stores uncompressed PCM data. FLAC compresses losslessly.

A four-minute stereo song at 44.1 kHz / 16-bit:

AIFF: approximately 40 MB

FLAC: approximately 22-28 MB (varies with content -- highly dynamic music compresses less than simple audio)

FLAC is 30-50% smaller than AIFF with no quality penalty. For large collections this matters. 1,000 songs in AIFF takes about 40 GB. The same library in FLAC takes about 22-28 GB.

Compatibility

AIFF has better native support in Apple's ecosystem. iTunes, Logic Pro, GarageBand, Final Cut Pro, and most Mac audio hardware work with AIFF without any configuration.

FLAC has better support across all other platforms. Android, Linux, most portable audio players, and the majority of Windows software handle FLAC without issues.

Neither format streams well. Spotify, Apple Music, and Tidal do not use AIFF or FLAC for delivery (they transcode to their own formats). For streaming services, format choice is irrelevant.

Metadata Support

FLAC wins here. FLAC uses Vorbis comment tags -- flexible, widely supported, and easy to edit with any tagger. It stores artist, album, year, genre, track number, cover art, lyrics, and custom fields reliably.

AIFF uses ID3 tags (the same system as MP3). ID3 support in AIFF is inconsistent across software. Some programs read AIFF ID3 tags correctly; others strip them or ignore them. iTunes handles AIFF tags well, but third-party tools can be unreliable.

If you care about album art and detailed metadata, FLAC is the safer choice.

Professional Audio Compatibility

Professional DAWs handle both. Pro Tools, Logic Pro, Ableton Live, and Reaper all work with AIFF and FLAC. Some older Pro Tools versions preferred AIFF over FLAC -- check your specific DAW and version.

For sending audio to a mastering engineer or collaborator, ask what they prefer. Many professionals still use WAV as the standard exchange format, sidestepping the AIFF vs FLAC debate entirely.

Streaming Devices and Portable Players

FLAC is better supported on dedicated portable music players (Astell & Kern, FiiO, Sony Walkman NW-series). Most network streamers (Naim, Cambridge Audio, Sonos) play FLAC natively but may not support AIFF.

AIFF works reliably on Apple devices and Apple-centric setups. Outside Apple, FLAC is the safer bet.

Converting Between Them

Converting AIFF to FLAC or FLAC to AIFF is lossless. Because both are lossless formats, you can convert back and forth without any quality degradation. This is different from MP3 conversion where each encode loses data.

The Recommendation

Use FLAC if:

You are archiving a music collection for long-term storage

You use non-Apple devices or platforms

You want smaller file sizes without quality loss

You care about reliable metadata and tagging

Use AIFF if:

You are working in a Mac-only audio production environment

Your DAW or hardware specifically requires or prefers AIFF

You are delivering audio to clients in the Mac/Apple ecosystem

For most people building a lossless music library, FLAC is the better choice -- smaller, better supported outside Apple's ecosystem, and with more reliable metadata handling.