Format
FLAC, lossless audio that is smaller than WAV.
FLAC stores every sample of a recording and takes less room than a WAV. Decoding it gives back exactly what went in.
FLAC is written by a small converter built into this page, so it works in every browser.
Facts
The record.
Extension
.flac.
Compression
Lossless. The format is open, started in 2001, and was published as RFC 9639.
What it holds
1 to 8 channels, bit depths from 4 to 32 bits and a wide range of sample rates, with tags and cover pictures.
Who reads it
Android, current Apple and Windows software and most music players and streamers.
Typical size
Often 30 to 50 percent less than the WAV for music, much less for speech and silence, and little for noise.
In Flex Convert
Written from WAV and read in any browser. Our own FLAC decoder takes over when the browser's fails.
Measured examples
What we measured.
FLAC files made on this site from generated WAV files, and one FLAC converted onward.
| Test file | Size | Change | Time | Result |
|---|---|---|---|---|
| 90 s music with tags and coverChrome | 2.6 MB → 1.7 MB | 34 percent smaller | 770 ms | Title, artist and album kept · Cover not kept |
| 90 s musicChrome | 16 MB → 2.9 MB | 82 percent smaller | 570 ms | Samples identical |
| 60 s noise, 24-bit 96 kHzChrome | 35 MB → 14 MB | 59 percent smaller | 1.1 s | Samples identical |
Measured on November 7, 2026 in Google Chrome 157, on Apple M1 Pro. Times run from pressing Convert to the result being ready, with the page already loaded. Likeness is PSNR against the original: higher is closer, and above 40 dB the difference is hard to see. Every test file was generated for these measurements, none is anyone else's work, and each is described on the About page.
A 90-second music-like WAV went from 16 MB to 2.9 MB in 567 milliseconds, and its samples came back identical. 60 seconds of 24-bit pink noise went from 35 MB to 14 MB, still 24-bit. A FLAC with title, artist and album tags kept them when converted to M4A, but not its cover.
Good to know
The lossless trade.
You keep everything; the size depends on the sound.
What lossless means
Decoding a FLAC produces the same samples as the file it came from. Nothing is approximated, so you can convert as often as you like and never lose anything. The size depends on the sound: noise leaves the coder little to remove, as the 24-bit noise file shows.
Why people choose it
It keeps a rip or a master at full quality in less space than WAV, with proper tags and a cover picture. It plays on most phones and music apps, which WAV often does not do gracefully.
Where it falls short
Some editing software, samplers and broadcast systems accept only WAV, and a few cars and older players do not know FLAC. For a small file on a phone, use M4A.
Choosing
When to pick it, and when not to.
A format is a trade. These are the trades this one makes.
Keep FLAC when
you archive music or keep a master, and want the original quality for less than WAV.
Convert to M4A when
the file goes on a phone or in a car and size matters more than the last bit of detail.
Convert to WAV when
an editor or a sampler needs it.