Free FLAC sample files
Lossless compressed audio: every sample of the original is recovered exactly. Download valid FLAC test files in 4 exact sizes, from 100 KB to 5 MB, each with a checksum.
- Extension
- .flac
- MIME type
- audio/flac
- Kind
- Binary
- Category
- Audio
FLAC files by size
Every file below is a valid Free Lossless Audio Codec file of exactly the stated size. Open a file's page for its checksum and contents, and to preview it in your browser before downloading.
| File | Size | Contents | Download |
|---|---|---|---|
| 100 KB FLAC samplesample-flac-100kb.flac | 100 KB102,400 bytes | 0.6 s | Download FLAC |
| 500 KB FLAC samplesample-flac-500kb.flac | 500 KB512,000 bytes | 2.9 s | Download FLAC |
| 1 MB FLAC samplesample-flac-1mb.flac | 1 MB1,048,576 bytes | 5.9 s | Download FLAC |
| 5 MB FLAC samplesample-flac-5mb.flac | 5 MB5,242,880 bytes | 29.7 s | Download FLAC |
What is a FLAC file?
FLAC compresses audio without discarding anything. It predicts each sample from the ones before it and stores only the difference, which typically brings music down to between half and two thirds of its size as WAV. Decoding gives back the original samples bit for bit.
A file starts with the marker "fLaC" and a STREAMINFO block that records the sample rate, the channels, the total number of samples and an MD5 checksum of the decoded audio. Tags, cover art and padding follow in further metadata blocks, and then the audio in frames that each carry their own checksum.
How to recognise a FLAC file
Software recognises a FLAC file by its file signature: fixed bytes at the start of the file, also called magic bytes or a magic number.
| Extension | .flac |
|---|---|
| MIME type | audio/flac |
| Also seen as | audio/x-flac |
| Standard | RFC 9639 (2024) |
| Compression | Lossless; linear prediction with Rice coding |
| Sample formats | 4 to 32 bits per sample, up to 8 channels |
| Metadata | STREAMINFO, Vorbis comments, pictures, padding, seek table |
What to test for
These are the behaviours that most often go wrong when software handles FLAC files.
- Some tagging tools put an ID3 tag in front of the stream. The signature then no longer sits at byte 0, and a strict parser rejects a file that most players accept.
- The MD5 checksum in STREAMINFO lets software prove that a decode is correct, yet few applications check it. A value of all zeros means the encoder did not record one.
- Cover art lives in the metadata, so a three-minute song can carry several megabytes before its first audio frame.
Strengths of FLAC
- Lossless: decoding returns the original samples exactly, at roughly half the size of WAV.
- Checksums in every frame and for the whole stream make corruption detectable.
Limitations of FLAC
- Several times larger than MP3 or AAC at transparent quality.
- Encoding takes more processing than writing raw PCM.
Typical uses of FLAC test files
- Testing audio upload where lossless input is accepted
- Checking transcoding to MP3, AAC or Opus
- Verifying duration and tag reading
- Testing that a decode matches the stored MD5 checksum
Software that opens FLAC
- Chrome, Firefox, Safari and Edge
- VLC, foobar2000 and most media players
- Android, iOS and Windows, natively
- FFmpeg and the reference flac tool
Specifications
Related
FLAC sample files: questions
- Why are the FLAC samples about as large as the WAV samples?
- To reach an exact byte count, the samples store their audio in "verbatim" subframes, the uncompressed form FLAC falls back on when prediction does not help. The files are fully valid, and decode to exactly the same samples as the WAV files.
- What audio is on the FLAC samples?
- A short synthesised musical phrase that repeats, as 16-bit stereo at 44,100 Hz. It was generated by code for this site and is free of any music copyright.
- What is the MIME type of a FLAC file?
- The MIME type is audio/flac. You will also meet audio/x-flac in practice. The file extension is .flac.
- Is a sample FLAC file the same as a dummy or example FLAC file?
- Yes. Sample, test, dummy and example FLAC files are different names for the same thing: a FLAC file with known contents that stands in for a real one. Any file on this page will do wherever a tutorial or a test plan asks for a dummy FLAC file.