Audio format
What is a .flac file?
FLAC (Free Lossless Audio Codec) compresses audio without losing anything. The decoded sound is identical to the original, in roughly half the space of a WAV file.
It’s open and royalty-free, and the usual format for music archives. Files are still several times larger than an MP3.
fileclay opens and writes FLAC
FLAC vs WAV vs MP3
| FLAC | WAV | MP3 | |
|---|---|---|---|
| Compression | Lossless | None | Lossy |
| Size per minute | Roughly half of WAV | About 10 MB | 1 to 2.4 MB |
| Metadata | Vorbis comments | Limited | ID3 tags |
| Playback | Most players | Everywhere | Everywhere |
| Best for | Archiving music | Recording, editing | Sharing |
When to use FLAC
Good for
- Archiving a music collection
- Ripping CDs with no loss
- Keeping a master you can convert later
Not a good fit
- Phones with little storage
- Older car stereos and players
- Sending audio by email
How to open .flac files
| Platform | App | Notes |
|---|---|---|
| Windows | Media Player | Built in |
| macOS | Music, QuickTime Player | Current versions |
| Android | Most music apps | Built in |
| Browsers | Chrome, Safari, Firefox, Edge | Drag the file into a tab |
| Any system | VLC | Free |
Convert FLAC files
How to identify a .flac file
Every FLAC file starts with the four letters “fLaC”.
66f
4CL
61a
43C
It’s read here, in your browser. Only the first bytes.
Your file
What comes after
STREAMINFOSample rate, channels and length
MetadataTags, cover and seek table
FramesThe compressed audio
Questions about FLAC
Does FLAC sound better than MP3?
It’s exact, while MP3 discards detail. At high bitrates many listeners can’t tell them apart.
Is FLAC the same quality as WAV?
Yes. The decoded audio is identical.
Does converting MP3 to FLAC improve quality?
No. It only stores the MP3’s sound in a larger file.
Does iPhone play FLAC?
Yes, in the Files app and in apps that support it.