FLAC is lossless: decoding a FLAC file gives back exactly the audio that was recorded or ripped. MP3 is lossy: it removes sounds that a psychoacoustic model predicts you will not notice, which makes files 4 to 10 times smaller.
In blind tests most people cannot reliably tell a well-made 320 kbps MP3 from the lossless original on typical headphones. At 128 kbps the difference is much easier to hear, especially in cymbals, reverb tails and applause.
FLAC and MP3 side by side
| FLAC | MP3 320 kbps | |
|---|---|---|
| Quality | Bit-perfect copy | Very close, some detail removed |
| 4-minute song | ≈ 25–30 MB | ≈ 9.6 MB |
| Hi-res support | Up to 24-bit / 384 kHz | Max 48 kHz |
| Compatibility | Most players, not Apple Music | Plays everywhere |
| Editing and re-encoding | No quality loss | Loses more each time |
When to keep FLAC
- Archiving a CD collection or your own recordings, so you can convert to any format later without generation loss.
- Listening on a good DAC and headphones or speakers, where small differences may matter to you.
- Editing, remixing or mastering, where lossy files degrade with every save.
When MP3 (or AAC) is enough
- Phones and players with limited storage.
- Car stereos, Bluetooth speakers and earbuds: Bluetooth re-encodes the audio anyway.
- Podcasts, audiobooks and voice recordings, where 64 to 128 kbps is plenty.
A practical approach
Keep a lossless master library in FLAC and make MP3 or AAC copies for portable devices. Converting from FLAC each time gives the best possible MP3, while converting MP3 to FLAC never brings quality back.
Frequently asked questions
Is 320 kbps MP3 as good as FLAC?
Not technically, but for most listeners on most equipment it is indistinguishable in blind tests.
Does converting MP3 to FLAC improve quality?
No. It only makes the file bigger. The missing detail cannot be restored, which is exactly how fake lossless files are made.
Is AAC better than MP3?
At the same bitrate AAC usually sounds a little better, especially below 192 kbps. Both are close to transparent at 256 kbps and above.
Related tools
FLAC to MP3 Converter
Shrink lossless FLAC to MP3 for any player.
How to Tell if a FLAC File Is Really Lossless
Spot FLAC and WAV files that were made from MP3s.
Audio Bitrate Explained: Which Bitrate Should You Use?
Which bitrate to pick for music, voice and video.
FLAC to ALAC Converter
Lossless FLAC to Apple Lossless for iPhone and Mac.