FLAC vs WAV: Quality, File Size and Which to Use

FLAC and WAV are both lossless formats, which means neither one throws any sound away. So the useful question is not which one sounds better, because they sound the same. It is which one is more practical for what you are doing. This guide compares file size, tags, device support and editing, explains the one catch that really can cost you quality, and ends with a simple rule for choosing.

The short answer

• Sound: identical. A FLAC decodes to exactly the same samples as the WAV it came from.
• Size: FLAC is usually 50 to 70% of the WAV size.
• Tags and cover art: FLAC handles them well. WAV support is patchy.
• Support: WAV opens almost everywhere. FLAC plays on all modern systems, but Apple's Music app will not import it.
• Rule of thumb: store and listen in FLAC; edit, or feed fussy hardware, in WAV.

Why FLAC and WAV sound the same

A WAV file usually stores PCM audio: a plain list of measurements of the sound wave, kept exactly as recorded. FLAC takes those same measurements and packs them into less space, a bit like a ZIP file built for sound. It predicts each measurement from the ones before it and stores only the small error in that prediction. When you play the file, the decoder reverses the process and rebuilds every measurement exactly.

The FLAC standard, published by the IETF as RFC 9639 in December 2024, defines it as lossless: the decoder must give back exactly the audio that went in. Every FLAC file also stores an MD5 checksum of the original, unencoded audio. That lets software prove that a decoded file matches the source bit for bit.

So if you compare a FLAC and a WAV of the same recording and hear a difference, something else changed. The usual causes are a volume difference, a different sample rate or bit depth, or a player that processes one file and not the other.

File size compared

Sizes are in decimal megabytes and gigabytes. How much FLAC saves depends on the music. Quiet, simple recordings such as solo instruments or speech shrink the most. Loud, dense modern masters shrink the least, because there is less pattern for the encoder to predict.

FLAC has compression levels from 0 to 8, with 5 as the default. A higher level makes a slightly smaller file but takes longer to encode. Every level decodes to exactly the same audio, so the level never changes the sound. Past level 5, the extra saving is small.

Tags and cover art

FLAC stores tags such as title, artist and album as Vorbis comments, and it can embed cover art in the file. Music players, library apps and media servers read these reliably, which makes FLAC easy to organize.

WAV can hold tags too, but in several competing ways: an INFO chunk, an ID3 chunk or broadcast (BWF) data. Apps do not all read the same one, so artist names and artwork often disappear when files move between programs. For a music library you want to browse by artist and album, FLAC is the better home.

Device and software support

• Windows: plays FLAC natively since Windows 10.
• Mac: macOS 10.13 High Sierra and later can play FLAC, but Apple's Music app and iTunes will not add FLAC files to your library. Convert them with our FLAC to ALAC converter to keep full quality in Apple's apps. Our FLAC vs ALAC guide explains the difference.
• iPhone and iPad: iOS 11 and later can play FLAC files, but the Music app will not import them. See how to play FLAC on iPhone.
• Android: has supported FLAC since Android 3.1.
• WAV: opens in almost every audio editor, video editor, sampler and player, old or new. When a device or program refuses your FLAC, WAV is the safe fallback.

Editing and music production

Many editors can open FLAC, but WAV is still the standard working format. There is no decoding step, every plugin and program accepts it, and broadcast workflows use the BWF version of WAV for their own metadata. A common approach is to record and edit in WAV, then keep FLAC copies of finished work. For project-level advice, read FLAC vs WAV for music production.

The 24-bit catch: how quality can be lost

FLAC to WAV and WAV to FLAC are lossless only when the bit depth and sample rate stay the same. Two things can quietly break that:

• A converter that always writes 16-bit WAV. For a CD-quality (16-bit) FLAC, the result is an exact copy. For a 24-bit FLAC, from a hi-res store or a studio, the extra 8 bits are dropped.
• Resampling. Converting 96 kHz audio to 44.1 kHz changes the audio, even if both files are "lossless" formats.

We test our own tools for this. Our WAV to FLAC converter keeps the bit depth and sample rate: a 24-bit WAV comes out as a 24-bit FLAC. Our FLAC to WAV converter does the same in reverse: a 16-bit FLAC gives a 16-bit WAV and a 24-bit FLAC gives a 24-bit WAV, at the original sample rate. We sent 16-bit and 24-bit WAV files to FLAC and back, and every audio sample came back identical. The one thing FLAC cannot hold is 32-bit float audio: our converter saves a float WAV as 24-bit FLAC, so keep float originals.

Hi-res FLAC and WAV: is 24-bit/96 kHz worth it?

Both formats can hold hi-res audio. FLAC supports 4 to 32 bits per sample and very high sample rates, and WAV can hold the same. A 24-bit/96 kHz file is about 3.3 times the size of the same music at CD quality, in either format.

For recording and editing, 24-bit is clearly useful. It leaves far more room below the loudest peak (about 144 dB against 96 dB in theory), so quiet parts stay clean after heavy processing.

For listening, the evidence is mixed. In 2016, Joshua Reiss reviewed 20 published listening tests in the Journal of the Audio Engineering Society. He found that listeners could tell hi-res from standard CD-quality audio slightly, but measurably, more often than chance, and that the effect was much stronger in trained listeners. Other researchers have pointed out that the overall result was only a little better than guessing. So the honest advice is: if you can hear a difference in your own blind test, keep the hi-res files. If you cannot, CD-quality FLAC saves a lot of space. Our sample rate guide explains what the higher numbers capture.

How to check a file's bit depth and sample rate

Before you convert or delete anything, check what you actually have:

• MediaInfo, a free app for Windows, Mac and Linux, shows the bit depth and sampling rate of any audio file.
• metaflac, which comes with the official FLAC tools, lists a FLAC file's details, including bits per sample, with its list option.
• ffprobe, part of FFmpeg, prints a line such as "Audio: flac, 96000 Hz, stereo, s32 (24 bit)" for a 24-bit file.

If a file says 16-bit and 44.1 kHz, it is CD quality, and any lossless converter will copy it exactly. If it says 24-bit, make sure your converter keeps 24-bit output.

How to check that a FLAC file is still intact

Because every FLAC file stores a checksum of its original audio, you can test it years later. The official flac command-line tool has a test mode (flac -t) that decodes the file and compares the result with the stored checksum, so silent damage from a failing drive shows up as an error. Standard WAV files have no built-in checksum. A damaged WAV may simply play with a click or a gap, and you might never notice.

Common myths about FLAC and WAV

• "FLAC is compressed, so it must sound worse." Its compression works like a ZIP file: nothing is thrown away.
• "Higher compression levels lower the quality." They only change file size and encoding time.
• "WAV sounds warmer than FLAC." Both hold the same samples. A difference in a comparison comes from volume, settings or expectations, not the format.
• "Converting back and forth wears out the file." Not if the bit depth and sample rate stay the same.

What about AIFF and ALAC?

Apple systems have the same split. AIFF is the uncompressed counterpart of WAV, and Apple Lossless (ALAC) is the compressed, lossless counterpart of FLAC. The sound is identical across all four; the choice comes down to which apps and devices you use. See WAV vs AIFF and FLAC vs ALAC for the details.

FLAC vs WAV for archiving

For most personal archives FLAC is the better choice: it takes less space, keeps tags with the audio, and its checksum lets you test old files for damage years later. The IETF standard was written with archiving and preservation in mind. Some professional archives still keep WAV or BWF because it is the simplest possible format. Our WAV vs FLAC for archiving guide weighs both sides.

Which should you use?

Converting between FLAC and WAV

Convert WAV to FLAC to save space and add proper tags. Convert FLAC to WAV when an editor, sampler or device will not open FLAC. Both run in your browser with FFmpeg, so your files are never uploaded. Free users get 5 conversions per month. The output is limited to the first 10 seconds as a preview, with a 20MB input file size limit. Upgrade to Pro for unlimited, full-length conversions.

The bottom line

FLAC and WAV hold the same sound. FLAC is the smarter way to store and listen: smaller files, good tags and a built-in check that the audio is intact. WAV is the smarter way to work: it opens everywhere and needs no decoding. Keep your bit depth and sample rate the same when you convert between them, and you can switch back and forth as often as you like.