FLAC vs WAV: Sound Quality, File Size, and Which Lossless Format to Use
FLAC vs WAV: The Short Answer
FLAC vs WAV is a comparison between two lossless audio formats, so the answer is not about sound quality. A WAV file stores raw, uncompressed PCM audio. A FLAC file stores the same PCM audio with lossless compression, the way a ZIP file stores a document. Decode the FLAC and you get back every sample of the original WAV, bit for bit.
The real differences are practical:
- Size: FLAC is usually 50-70% of the WAV's size. Exactly how much smaller depends on the music.
- Metadata: FLAC has proper tags and embedded cover art. WAV tagging is limited and inconsistent between apps.
- Compatibility: WAV opens in every DAW, audio editor, and hardware sampler. FLAC is the standard for music players, but some editing software won't import it.
- Workflow: WAV for recording and editing, FLAC for storing and listening.
If you're using an Apple Music library, there's a third option, ALAC, and a fourth, AIFF. Both are covered below.
What Is FLAC?
FLAC (Free Lossless Audio Codec) is an open, royalty-free audio format maintained by the Xiph.Org Foundation. It was first released in 2001, and in December 2024 the IETF published it as a formal standard, RFC 9639.
FLAC works by predicting each audio sample from the samples before it and storing only the small error between the prediction and the real value. Those errors take far fewer bits than the raw samples, so the file shrinks, and because nothing is thrown away, the decoder can rebuild the original exactly. If you want the general idea behind this, see what is lossless compression.
What the format supports, per the spec:
- 4 to 32 bits per sample, from 16-bit CD audio to 24-bit studio masters and beyond
- Sample rates up to 1,048,575 Hz, which covers 44.1, 48, 96, and 192 kHz
- 1 to 8 channels
- Tags (Vorbis comments: artist, album, track number, and any custom field), embedded pictures, cue sheets, and a seek table
- An MD5 checksum of the original audio stored in the header, so a decoder can verify the file is intact
That last point is underrated: flac -t file.flac checks a FLAC for corruption, which WAV can't do.
What Is WAV?
WAV (Waveform Audio File Format) was introduced by Microsoft and IBM in 1991. It's a RIFF container that usually holds uncompressed PCM audio, the same samples a CD player or audio interface works with.
Because there's nothing to decode, WAV is the lowest-friction format for editing. Every DAW records to it and most field recorders write it, which is why it's still the default for mixing, mastering, and broadcast.
The weaknesses come from its age:
- No compression. A CD-quality stereo WAV takes about 10.6 MB per minute.
- Weak metadata. WAV has a basic INFO chunk, and some apps add ID3 tags, but support differs from app to app. Embedded cover art is unreliable.
- A 4 GB ceiling. The RIFF header stores the file size in 32 bits, so a standard WAV tops out at 4 GB (about 6 hours 45 minutes of CD-quality stereo, or about 2 hours at 24-bit/96 kHz). Long recordings use extensions such as RF64 or BW64, which keep the
.wavextension but aren't readable by every app.
FLAC vs WAV Sound Quality: Is FLAC Better Than WAV?
When it comes to FLAC vs WAV sound quality, the two are identical. This isn't a matter of opinion or listening tests. Lossless means the decoded output equals the input, sample for sample.
You can prove it on your own files. FFmpeg can hash the decoded audio stream of any file:
ffmpeg -i song.wav -map 0:a -f md5 -
ffmpeg -i song.flac -map 0:a -f md5 -
When we tested this on a WAV, the FLAC made from it, and a WAV decoded back from that FLAC, all three printed the same MD5. So did an ALAC and an AIFF copy of the same audio.
So is FLAC better than WAV? For sound, no; it's a tie. For storage and listening, FLAC usually wins, because you get the same audio in less space with real tags. For editing, WAV usually wins because of compatibility.
If two versions of a song sound different, the cause is somewhere else: a different master, a different sample rate, a louder file, or a lossy file pretending to be lossless. The line that matters is lossless vs lossy, not FLAC vs WAV. Our guide to the difference between lossy and lossless covers that split.
FLAC vs WAV File Size
Uncompressed audio size is simple to calculate:
sample rate × bit depth × channels ÷ 8 = bytes per second
For CD-quality audio (16-bit, 44.1 kHz, stereo):
44,100 × 16 × 2 ÷ 8 = 176,400 bytes per second (1,411.2 kbps)
That works out to about 10.6 MB per minute. FLAC's savings depend on the music: quiet, sparse recordings like solo piano or classical compress more, while loud, dense masters compress less. A typical range is 50-70% of the WAV's size.
| Track length (16-bit / 44.1 kHz stereo) | WAV / AIFF | FLAC (typical) | MP3 320 kbps (lossy, for reference) |
|---|---|---|---|
| 1 minute | 10.6 MB | 5.3-7.4 MB | 2.4 MB |
| 3 minutes | 31.8 MB | 15.9-22.2 MB | 7.2 MB |
| 3.5 minutes | 37.0 MB | 18.5-25.9 MB | 8.4 MB |
| 4 minutes | 42.3 MB | 21.2-29.6 MB | 9.6 MB |
MB = 1,000,000 bytes. WAV and AIFF sizes are exact apart from a header of a few dozen bytes; FLAC sizes vary by track.
Hi-res audio scales up fast. A 4-minute track at 24-bit/96 kHz is 96,000 × 24 × 2 ÷ 8 = 576,000 bytes per second, or about 138 MB as WAV. On a 1,000-album library, FLAC's savings add up to hundreds of gigabytes.
The bitrate math behind these numbers is explained in what is audio bitrate.
FLAC compression levels
FLAC encoders offer compression levels. The reference flac encoder uses 0 to 8 (default 5), and FFmpeg's encoder accepts -compression_level from 0 to 12. Higher levels make slightly smaller files and encode more slowly, but they don't affect quality, because every level is lossless. In our FFmpeg test, level 12 was less than 1% smaller than the default. The default is fine for almost everyone.
FLAC vs WAV Comparison Table
| FLAC | WAV | |
|---|---|---|
| Compression | Lossless compressed | None (uncompressed PCM) |
| Sound quality | Identical once decoded | Identical |
| Typical size vs WAV | 50-70% | 100% |
| Tags and cover art | Full tags, embedded pictures | Limited, inconsistent between apps |
| Built-in integrity check | Yes (MD5 of the audio) | No |
| Max file size | No practical limit | 4 GB (RF64/BW64 extend it) |
| DAW and editor support | Varies by app | Universal |
| Music players and phones | Very wide, except Apple Music | Wide, but tags show poorly |
| License | Open, royalty-free | Open, widely documented |
| Best for | Libraries, archives, downloads | Recording, editing, delivery to studios |
ALAC vs FLAC: The Apple Question
ALAC (Apple Lossless Audio Codec) is Apple's equivalent of FLAC. It's lossless, it usually lives in an .m4a file, and Apple released it as open source in 2011. Apple Music streams its lossless catalog in ALAC, at up to 24-bit/192 kHz for Hi-Res Lossless.
On sound quality, ALAC vs FLAC is another tie: both decode to the original PCM. The differences are about ecosystems:
| ALAC | FLAC | |
|---|---|---|
| Container | .m4a (MPEG-4) | .flac |
| Size | Similar; often slightly larger than FLAC | Similar; often slightly smaller |
| Apple Music on Mac, iPhone, iPad | Imports and plays | Won't import |
| Android, Windows, Linux players | Supported by many, not all | Near-universal |
| Hi-res download stores | Sometimes offered | Almost always offered |
In our test, the ALAC file was about 6% larger than the FLAC made from the same WAV. The gap varies by track but is never dramatic.
Rule of thumb: if your music lives in Apple Music, use ALAC. If it lives anywhere else, use FLAC. Converting between the two is lossless, and FFmpeg carries tags and cover art across (commands below).
Can a Mac play FLAC?
Partly. Since macOS High Sierra, QuickTime Player and Quick Look (select a file in Finder and press the space bar) play FLAC. The Music app still doesn't import FLAC, so FLAC albums won't appear in your Apple Music library or sync to an iPhone through it. On an iPhone, the Files app can play a FLAC file, but the Music app can't add it to your library. Third-party players such as VLC play FLAC on both.
If you're coming from Apple's lossy side instead, what is the AAC codec explains how AAC differs from ALAC despite sharing the .m4a extension.
AIFF vs WAV
AIFF (Audio Interchange File Format) is Apple's uncompressed format from 1988. AIFF vs WAV is the simplest comparison in this post: both hold uncompressed PCM, so for the same audio they're the same size and sound identical. AIFF stores samples in big-endian byte order and WAV in little-endian, which matters to software and not to your ears.
The practical differences:
- Tags: AIFF handles ID3 tags and artwork more reliably in Apple Music and in many DJ apps, which is why some DJs keep their libraries in AIFF instead of WAV.
- Platform default: WAV is the norm on Windows and in most studio deliveries. AIFF is the classic Mac format, and macOS apps read both.
- Size limit: AIFF also uses 32-bit size fields, so it has the same roughly 4 GB ceiling as WAV.
If you need uncompressed audio and good tags in Apple Music, use AIFF. If you need uncompressed audio for someone else's studio, use WAV.
Which Lossless Format Should You Use?
| Use case | Best choice | Why |
|---|---|---|
| Archiving a CD or music collection | FLAC | Smaller, tagged, self-verifying, open format with no vendor lock-in |
| Recording, editing, mixing | WAV (or AIFF on Mac) | Universal DAW support, no decode step |
| Delivering stems or masters | WAV, unless the client asks otherwise | It's what studios, distributors, and mastering engineers expect |
| Apple Music library | ALAC | The only lossless format Music imports with full tags |
| Android phone or a hi-fi player | FLAC | Native support, smaller files, tags and artwork |
| DJ library | AIFF or FLAC, depending on your DJ software | Both keep tags; check what your software and club players read |
| Phone storage is tight | A lossy copy (AAC or MP3) | Lossless files are roughly 2-4x larger than a 320 kbps MP3 |
A common setup is to keep a FLAC archive as the master and make lossy copies for phones and cars. If that's your plan, FLAC to MP3 and WAV to MP3 walk through the lossy side. For other ways to save space on raw recordings, see how to compress WAV files.
How to Convert Between FLAC, WAV, ALAC, and AIFF
All of these conversions are lossless, so you can go back and forth freely. FFmpeg handles every direction. On a Mac, install it with brew install ffmpeg. Each command below was tested with FFmpeg's built-in encoders.
WAV to FLAC:
ffmpeg -i song.wav -c:a flac song.flac
# Smallest possible file (slower encode, same audio)
ffmpeg -i song.wav -c:a flac -compression_level 12 song.flac
FLAC to WAV:
# 16-bit source
ffmpeg -i song.flac -c:a pcm_s16le song.wav
# 24-bit source
ffmpeg -i song.flac -c:a pcm_s24le song.wav
Match the codec to the source's bit depth (ffprobe song.flac shows it). Basic tags such as title and artist carry over into the WAV's INFO chunk, but cover art doesn't.
FLAC to ALAC (for Apple Music), keeping tags and cover art:
ffmpeg -i song.flac -c:a alac -c:v copy song.m4a
The -c:v copy part copies the embedded artwork without re-encoding it. Leave it out if the FLAC has no picture.
WAV to AIFF:
ffmpeg -i song.wav -c:a pcm_s16be song.aiff
A whole folder of WAVs to FLAC:
for f in *.wav; do ffmpeg -i "$f" -c:a flac "${f%.wav}.flac"; done
Before deleting any originals, check a few files with the MD5 commands from the sound quality section. Matching hashes mean the conversion was bit-perfect.
Inside the Music app, you can also convert WAV or AIFF files to Apple Lossless: choose Music > Settings > Files > Import Settings, set Import Using to Apple Lossless Encoder, then select songs and choose File > Convert > Create Apple Lossless Version. Music can't read FLAC, so use FFmpeg for FLAC files.
For a broader look at shrinking audio, including when lossy is the smarter trade, see how to compress audio files.
Where Compresto Fits
Compresto doesn't convert between lossless audio formats; use FFmpeg or the Music app for that. It's a native Mac app for the files that usually take more space than your music: videos, images, GIFs, and PDFs, compressed in batches on your Mac with nothing uploaded. It can also extract an MP3 from a video when you only need the sound.
Frequently Asked Questions
Is FLAC better than WAV?
For storing and listening, usually yes: the same audio in 50-70% of the space, with real tags. For editing and recording, WAV is better because every audio tool reads it.
Does FLAC sound better than WAV?
No. Decoded FLAC is bit-identical to the source WAV. Compare MD5 hashes of the decoded audio to check.
Should I use ALAC or FLAC?
ALAC if you use Apple Music, since the Music app won't import FLAC. FLAC for everything else. Converting between them is lossless.
Can a Mac play FLAC files?
QuickTime Player and Quick Look play FLAC. The Music app doesn't import it, so convert to ALAC for your Apple Music library.
Is AIFF better than WAV?
No difference in sound or size. AIFF has better tag support in Apple apps; WAV is the studio and Windows default.
Can I convert WAV to FLAC and back without losing quality?
Yes. Use the same bit depth and sample rate, and the round trip is bit-perfect.
The Short Version
FLAC and WAV sound identical. Keep music in FLAC (smaller, tagged, self-checking), work on audio in WAV, use ALAC for Apple Music, and convert between them freely with FFmpeg.