Short answer: there is no difference in sound. A FLAC holds exactly the same audio as the WAV it came from, in a smaller file. So for keeping music, FLAC wins, and you only need WAV when a program won't take FLAC. There is one way to lose quality while converting between them, though, and it's easy to do without noticing.
Rather than repeat the usual claims, we checked. On 1 November 2026 we took 8 real recordings in FLAC from Wikimedia Commons (a symphony, solo piano, a 1920s jazz transfer, violin, dobro, synth, a synth demo and a street recording), turned each into a WAV and back again, and compared the audio sample by sample.
The quick comparison
| FLAC | WAV | |
|---|---|---|
| Sound quality | Same | Same |
| File size | Smaller | 1.4 to 4.6 times bigger in our test |
| Notices if the file gets damaged | Yes, it stores a checksum | No |
| Title, artist, cover art | Yes, and Windows shows them | Limited; Windows didn't show them |
| Size limit | None you'll reach | 4 GB per file |
| Opens in editors and older equipment | Most, not all | Almost everything |
Is the quality really the same?
Yes. FLAC compresses the way a ZIP file does: everything comes back when you open it. In all 8 recordings, going from WAV to FLAC and back to WAV gave us the same samples, with not a single one different. The checksum stored inside each original FLAC matched as well, so what we decoded was also what the person who made the file had encoded.
That settles the listening question too. If two files contain the same numbers, your speakers receive the same signal, so any difference you hear comes from something else, such as a different player, a different volume or a different master.
How much bigger is a WAV?
Articles on this give figures from 30% to more than double, and they're all partly right, because it depends on the music. WAV size depends only on the length and format, while FLAC gets smaller the simpler the sound is.
| Recording | Length | FLAC | WAV | WAV is |
|---|---|---|---|---|
| Solo piano, Schubert (24-bit) | 7:46 | 26.8 MB | 123.3 MB | 4.6 times bigger |
| Synth demo (16-bit) | 0:29 | 2.2 MB | 5.1 MB | 2.3 times |
| Dark synthwave (24-bit) | 0:38 | 5.3 MB | 10.0 MB | 1.9 times |
| Solo violin (24-bit mono) | 3:22 | 16.2 MB | 29.1 MB | 1.8 times |
| Beethoven symphony (24-bit) | 5:49 | 57.0 MB | 100.6 MB | 1.8 times |
| Dobro (24-bit mono) | 0:39 | 3.2 MB | 5.1 MB | 1.6 times |
| 1920s jazz transfer (96 kHz, 24-bit) | 3:33 | 81.2 MB | 122.6 MB | 1.5 times |
| Marching band in the street (24-bit) | 2:06 | 25.2 MB | 36.3 MB | 1.4 times |
The middle of the range was about 1.8 times. Noise is the hardest thing to compress, so it fits that an old transfer and a street recording saved the least, and a clean solo piano saved the most. For a whole library, planning on a WAV being a little under twice the size is a fair guess.
The mistake that does lose quality
Going from FLAC to WAV can quietly lower the resolution of a 24-bit file. Some online converters write
16-bit WAV, always or by default, and so does ffmpeg if you don't ask for anything else. We ran
ffmpeg -i in.flac out.wav on a 24-bit test file: it gave no warning, the WAV was 16-bit,
and 99.6% of the samples had changed. Adding -c:a pcm_s24le changed none of them.
To avoid it, look at the WAV's bit depth afterwards, or use FLAC to WAV, which keeps the original depth by default and compares every result with the checksum stored in the FLAC. It runs in your browser and nothing is uploaded. In our test it turned the 57 MB Beethoven file into a 100 MB WAV in under 2 seconds on a desktop PC, with every sample unchanged.
FLAC can tell you when it's damaged. WAV can't.
This is the difference most comparisons skip, and it matters for an archive. FLAC stores a fingerprint of the audio, so a damaged file can be spotted. We changed 40 bytes in the middle of a test FLAC, and cut another copy off at 60% as if a download had stopped. Both still opened and gave a WAV that played, and both failed the checksum check. A WAV has no such fingerprint, so a damaged one simply plays with a click or a gap, and nothing tells you unless you happen to hear it.
Tags: what Windows actually shows
We checked this in File Explorer on Windows 11. A tagged FLAC showed its title, artist, album, year and track number. A WAV showed none of them, even though the tags were in the file. It made no difference whether they were written as INFO tags by ffmpeg or by our converter, or as an ID3 tag. If you browse your music by artist, that alone is a good reason to keep FLAC. WAV has no standard place for cover art either.
So which should you use?
- Keeping music you own: FLAC. It's smaller, keeps its tags and can reveal damage.
- A program refuses FLAC: make a WAV copy for that job and keep the FLAC.
- Burning an audio CD: 16-bit, 44.1 kHz WAV. A CD can't hold more, so this is the one case where you should choose a lower bit depth.
- Recording or editing a project: WAV is the usual working format, because it needs no decoding. Save the finished master as FLAC too.
- A phone or a car: neither, if space is short. Make an MP3 with FLAC to MP3 or WAV to MP3, and keep the original. Apple's Music app won't import FLAC at all.
Common problems
- The WAV is over 4 GB. A WAV can't go past that, which is about 6.7 hours at CD quality or 2 hours at 96 kHz, 24-bit. Cut it into parts first with Split Audio.
- The converted file sounds different. Check its bit depth and sample rate, then check the volume. If both are the same as the original, the audio is too.
- The checksum doesn't match. Download the FLAC again. If the second copy fails as well, the source file itself is damaged.
What we tested: FLAC decoding and integrity with ffmpeg 7.1 and with Chrome 156 and Edge 156, and File Explorer on Windows 11 (build 26300). Both browsers loaded FLAC and WAV and reported the right length. We didn't test phones, Macs, CD burners or DJ equipment, or listen to anything for differences, because identical samples leave nothing to compare.