FLAC file format: what it is and how to use it
FLAC compresses audio losslessly to half its size, with every sample preserved bit-for-bit, open and playable on everything made this century. Learn when to use it and what to choose instead.
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What is a FLAC file?
A .flac file is audio compressed with the Free Lossless Audio Codec, the Xiph.Org codec released in 2001 that predicts each sample and stores only the residual: typically 50–60% of the WAV size, decoding to bit-identical output. It is open, unencumbered, fast to decode, and the de-facto standard for anyone who wants a perfect copy without WAV's bulk.
When should you use FLAC?
- Music libraries that must stay perfect: rips, masters, downloads from Bandcamp and hi-res stores.
- Editing-safe exchange: move audio between tools without generation loss.
- Archiving: decode it in fifty years and get the same bits back.
When is another format a better fit?
Inside Apple's world ALAC is the twin choice. For listening on the go where space is tight, a good AAC or Opus encode is a fraction of the size. Lossless is for the library, lossy for the pocket. For raw recording and editing input, WAV remains the simplest capture.
The short version: FLAC is the lossless standard: half the size, all the data, supported everywhere worth mentioning.
How to open a FLAC file
On Windows
Double-click the file, or open it with Foobar2000.
On macOS
iTunes (via plugins) opens FLAC files on macOS.
In your browser
Open FLAC files right in a browser tab or with the dexrr viewer. No install, no upload.
Also opens in
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VLC -
Foobar2000 -
Audacity -
iTunes (via plugins)
View or convert FLAC files
A quick preview or a new format. No install, no upload.
FLAC technical details
- Full name
- Free Lossless Audio Codec
- Extensions
- .flac
- MIME type
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audio/flac, audio/x-flac - Magic bytes
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66 4C 61 43 (fLaC) - Compression
- Lossless
- Developer
- Xiph.Org Foundation
- Specification
- xiph.org
FLAC questions, answered
How do I open a .flac file?
Everything plays it: VLC, foobar2000, system players, phones and browsers. dexrr plays and converts flac files directly in your browser.
Can I convert FLAC files online?
Yes, dexrr converts flac locally in your browser: FLAC to MP3 for sharing, FLAC to WAV for editing or FLAC to ALAC for Apple libraries.
Is FLAC better than MP3?
For fidelity, objectively. It preserves every bit while MP3 discards audio permanently. For size and convenience, MP3 wins. Keep FLAC as master, MP3 as the handout.
Does converting FLAC to WAV improve quality?
No, the decoded PCM is identical; WAV just stores it uncompressed. Converting WAV back to FLAC also loses nothing.
Is the FLAC format outdated?
No, it is the entrenched standard for lossless audio, supported natively by modern OSes, players and browsers.