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WAV vs AIFF vs MP3: which format should you keep on a Mac?

Tested on macOS 26.4.1 (Tahoe), Apple M3 Max, 3 Sept 2026. Updated 2026-09-03.

WAV and AIFF are containers for the same uncompressed PCM audio, so a 24-bit 48 kHz recording is 16.5 MB per minute in either one. MP3 is lossy compression: 320 kbps is 2.4 MB per minute and throws away detail you cannot get back. Keep a WAV or AIFF master of anything you might edit, and make an MP3 copy for sharing.

Is AIFF the same quality as WAV?

Yes. Both store linear PCM samples; the difference is the wrapper. AIFF was developed by Apple in 1988 and stores samples big-endian; WAV is Microsoft's RIFF-based container and stores them little-endian (Wikipedia, AIFF). No sample values change when you convert one to the other.

A quick test on this Mac shows how close they are. A 10-second 24-bit 48 kHz stereo file written as WAV is 2,880,044 bytes; the same audio converted with afconvert -f AIFF -d BEI24 is 2,884,096 bytes. The 4 KB difference is header and chunk padding, not audio. Both play in QuickTime Player, Music, Logic Pro and every DAW. AirCheck records its master as 24-bit AIFF and converts to your chosen export format once, when the take stops, so you never handle the AIFF unless you want to. For per-minute sizes of each option see how big is an audio recording per minute.

Should I keep the MP3 or the WAV of a recording?

Keep the PCM file (WAV or AIFF) if you will do anything to the audio later: trim, normalize, remove noise, master, or convert to another compressed format. Every MP3 encode discards information, and re-encoding an MP3 to another lossy format stacks the losses. Apple's own guide warns that when you convert between compressed formats "you might notice a reduction in the sound quality" (Apple, Convert music file formats).

Keep only the MP3 when the source was already lossy and you will never edit the file: a YouTube capture, a podcast you listened to, a reference recording for your own notes. A 90-minute lecture as MP3 320 is 216 MB against 1,485 MB at 24-bit 48 kHz, and the source (a video call or stream) had far less detail than either. Size is the only reason to choose MP3, and 6.9 to 1 (16.5 / 2.4) is a large reason when you record every day. Storage math for both is in 16-bit vs 24-bit.

Which format works everywhere?

WAV is the safest exchange format. Windows, Linux, web upload forms, DJ software, and every DAW accept it, and 24-bit WAV is the standard delivery for mastering. AIFF is equally supported inside Apple software and most DAWs but occasionally rejected by web services and Windows tools that check the extension. MP3 plays on anything with a speaker.

Two practical limits matter. First, a standard WAV cannot exceed 4 GiB because the header stores the size in a 32-bit integer (Wikipedia, WAV); at 16.5 MB per minute that is about 4 h 8 min of 24-bit 48 kHz audio. Apple's afconvert -hf lists RF64 and BW64 as WAVE variants "for length over 4 GB", but support in third-party apps varies. Second, macOS itself ships no MP3 encoder: afconvert can read MP3 but the encode attempt fails, so you need the Music app, ffmpeg or LAME to create one. The details are in how to convert AIFF or WAV to MP3.

How do I convert between WAV, AIFF and MP3 on a Mac?

Lossless conversions are one command in Terminal with Apple's built-in afconvert, tested on macOS 26.4.1:

  1. AIFF to 24-bit WAV: afconvert -f WAVE -d LEI24 in.aiff out.wav
  2. AIFF to 16-bit WAV: afconvert -f WAVE -d LEI16 in.aiff out.wav
  3. WAV to 24-bit AIFF: afconvert -f AIFF -d BEI24 in.wav out.aiff
  4. Any PCM to AAC in an .m4a: afconvert -f m4af -d aac -b 256000 in.wav out.m4a

LEI24 means little-endian integer 24-bit, BEI24 big-endian, which is why WAV uses LE and AIFF uses BE. For MP3, afconvert -f MPG3 -d '.mp3' returns Error: ExtAudioFileSetProperty ('cfmt') failed ('fmt?') on this Mac; use ffmpeg -i in.wav -c:a libmp3lame -b:a 320k out.mp3 after brew install ffmpeg, or the Music app's File > Convert menu. AAC is covered in converting to M4A or AAC.

WAV vs AIFF vs MP3 for a stereo recording

FormatLosslessMB per minuteGB per hour10 s test file on disk (bytes)Standard macOS can write itMax file size
WAV, 24-bit 48 kHzyes16.50.972,880,044yes (afconvert)4 GiB
AIFF, 24-bit 48 kHzyes16.50.972,884,096yes (afconvert)not tested
WAV, 16-bit 48 kHzyes11.00.641,924,096yes (afconvert)4 GiB
MP3, 320 kbpsno2.40.14not testedno (needs ffmpeg, LAME or Music app)none in practice

MB per minute measured from 45 real recordings; the 10-second files were generated and converted with afconvert on macOS 26.4.1.

Where AirCheck fits

AirCheck ($39, macOS 14 or newer) sidesteps the question for most takes: it always captures a 24-bit AIFF master, then converts once to the export you chose, WAV 16-bit, WAV 24-bit or MP3 320 kbps, when you stop. You get one file in the format you actually wanted, with the size shown in the Library. That suits DJs who want a WAV master and podcast listeners who want a small MP3 without running Terminal afterwards.

When you do not need it: If you already have the file and only need to change its wrapper, afconvert is free, built in and faster than any app. Per-app mixing before the file is written is a different category of tool; AirCheck records one source per take.

AirCheck records what your Mac plays, or any input, to one file. $39 once.

Buy AirCheck for $39

macOS 14 or newer. One-off payment. Fourteen-day refund, no questions asked.

Questions people ask

Is AIFF better than WAV?

No. Both hold identical PCM samples and are the same size within a few kilobytes of header. AIFF is the Apple-native container; WAV is more widely accepted by Windows software and web uploads. Convert between them losslessly with afconvert.

Is MP3 320 as good as WAV?

It is close enough for listening, but it is lossy: information is removed and cannot be restored. At 2.4 MB per minute it is 6.9 times smaller than 24-bit 48 kHz PCM. Keep the PCM master for anything you might edit or re-encode.

Can macOS convert WAV to MP3 without extra software?

Not from Terminal: afconvert has no MP3 encoder and fails with a format error. The Music app can, via Music > Settings > Files > Import Settings and then File > Convert > Create MP3 Version. ffmpeg or LAME via Homebrew are the command-line options.

Which format do DJs record in?

Usually 24-bit WAV or AIFF at the interface's rate (44.1 or 48 kHz) for the master, then an MP3 for upload. A two-hour set is about 1.98 GB at 24-bit 48 kHz and 288 MB at MP3 320 kbps.

Sources

Hannes Hennerbichler builds AirCheck and records his own DJ sets with it through a Focusrite Scarlett 8i6. Every step on this page was run on the macOS version stated above. Drafted with AI assistance, checked and edited by the author. About