FLAC vs MP3: is lossless worth it?
FLAC shrinks audio without losing anything; MP3 shrinks it much further by leaving detail out. We measured both on the same music and checked the FLAC really is lossless.
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Quick answer: FLAC is lossless: our one-minute test decoded to exactly the same samples as the original WAV, at 4.37 MB instead of 10.58 MB. A 320 kbps MP3 of the same minute was 2.40 MB and a 128 kbps MP3 0.96 MB. Keep FLAC as your archive and for good headphones and hi-fi; use MP3 for phones, cars and anything that does not play FLAC.
Updated
Choose FLAC when
- You archive a music collection or CD rips: it is exact and you can make any other format later.
- You listen on good headphones or a hi-fi system and have the space.
- You buy music: many stores offer FLAC downloads.
Choose MP3 when
- The player does not take FLAC: many car stereos, older players and the Apple Music app.
- Space matters: a 320 kbps MP3 is about half the size of the FLAC.
- You share or upload the music.
The same minute of music, measured
| Format | Size | Lossless? |
|---|---|---|
| WAV | 10.58 MB | Yes |
| FLAC | 4.37 MB | Yes: decodes to the same samples as the WAV (MD5 checked) |
| MP3 320 kbps | 2.40 MB | No |
| MP3 128 kbps | 0.96 MB | No |
One minute of the Sintel trailer soundtrack (stereo, 44.1 kHz), made with standard free software on 20 October 2026. Sintel © Blender Foundation, CC BY 3.0.
How it works
- Drop your audio fileM4A, WAV, FLAC, OGG and more, any length. It stays on your computer.
- Pick the quality"Very good" suits speech and most music; "Best" for music you care about.
- Download the MP3Plays on every phone, computer, car stereo and audio editor.
How FLAC stays exact
FLAC works like a ZIP file made for sound: it predicts each sample from the ones before and stores only the small difference, so decoding gives back every sample exactly. How much it saves depends on the music: quiet, simple recordings shrink most, dense rock and electronic music least, usually to between a third and two thirds of the WAV.
Can you hear the difference?
Against a 320 kbps MP3, most people cannot, in blind listening on ordinary equipment. FLAC's real advantage is that it is a perfect master: convert it to any format later, as often as you like, without losing anything.
Measured, not promised
From our tests in Chrome on a 2019 Intel MacBook, October 2026. See all results.
Why your audio never leaves your computer
Online converters upload your file to their servers, convert it there and send it back. That is slow for long recordings, so free plans cap the length or the number of files, and your recording sits on someone else's computer.
Here your own computer does the work, inside this tab. Nothing is uploaded, so there is nothing to cap: no length limit, no daily limit and no sign-up.
Questions
Is FLAC better than MP3?
FLAC is exact, so it is the better master. For everyday listening, a 320 kbps MP3 is very hard to tell apart and half the size.
Does Apple Music play FLAC?
The Apple Music app does not import FLAC. Convert it to MP3, or to Apple's own lossless format, to use it there.
Can I convert a whole FLAC album to MP3?
Yes. Drop all the tracks together; they are converted one after another and download as a ZIP.
Can I convert several files at once?
Yes. Choose or drop several files together. They are converted one after another with the same settings, and you can download each one or all of them in one ZIP.
Is it really free?
Yes. Your computer does the work, so a file costs us nothing to convert. No account and no limits.
Is my file uploaded?
No. It is converted inside this browser tab and saved straight back to your computer.
Which browsers work?
Recent Chrome, Edge and Safari on a computer.
Can I use a video file?
Yes. Drop a video and you get its sound.