20 MB FLAC sample
A FLAC file of exactly 20,971,520 bytes. It is a valid Free Lossless Audio Codec file, generated by this site. Compare its checksum and test it with the parser used by your application. Use it wherever you need a 20 MB sample, test or dummy FLAC file.
Download
sample-flac-20mb.flac
20 MB20,971,520 bytes
Download 20 MB FLACCreated in your browser in a few seconds, then checked against the SHA-256 checksum. No sign-up.
- Type
- audio/flac
- SHA-256
113ab83100a9f2d2f03366929813b6fe1ebbaba87d0fc90e1eb9acfd65e7f9c6- Delivery
- Created in your browser from static generator assets (how it works).
What is in this file
1,280 FLAC frames (1 min 59 s) of a synthesised musical phrase that repeats every eight seconds. The samples are stored verbatim, so the audio decodes bit for bit to the matching WAV data. 0 bytes of a standard PADDING metadata block bring the file to the exact size.
| Duration | 1 min 59 s |
|---|---|
| Sample rate | 44,100 Hz |
| Channels | 2 (stereo) |
| Bit depth | 16-bit |
| Block size | 4,096 samples |
| Encoding | Verbatim subframes (lossless, not compressed) |
| Tags | Vorbis comment (title, artist, album) |
First bytes of the file
The first 64 bytes of sample-flac-20mb.flac as a hex dump: offset, bytes, then the same bytes as text. The FLAC signature is 66 4C 61 43.
00000000 66 4c 61 43 00 00 00 22 10 00 10 00 00 00 00 00 |fLaC..."........|
00000010 00 00 0a c4 42 f0 00 4f f2 35 80 1d ec fb 8e 0b |....B..O.5......|
00000020 a0 14 a8 6e 30 62 bd cd 40 62 04 00 00 78 19 00 |...n0b..@b...x..|
00000030 00 00 53 61 6d 70 6c 65 54 65 73 74 46 69 6c 65 |..SampleTestFile|Preview
Creates the file in your browser and shows it here. Nothing large is downloaded from our server.
Where 20 MB matters
A 20,971,520-byte file: right at the default attachment limit of Outlook, and just under the 25 MB ceilings of Gmail and GitHub web uploads. These are the default limits a file of this size is useful for testing:
| System | Limit | Note |
|---|---|---|
| Microsoft Outlook | 20 MB of attachments by default for internet mail accounts | This file is right at the limit; add a second attachment and it is exceeded. |
| Gmail | 25 MB per message | Under the limit, although email encoding adds about a third in transit. |
| GitHub web uploads | 25 MiB per file added through the browser | Accepted. Pushing with Git allows larger files. |
| Cloudflare Pages assets | 25 MiB per file | The largest round size that can be served as a static asset. |
| Amazon API Gateway | 10 MB payload | Rejected; the upload has to go directly to object storage. |
| ASP.NET Core (Kestrel) | About 28.6 MB request body by default | Accepted with room for the multipart overhead. |
Use this file for
- Testing image resizing and memory use
- Verifying duration and tag reading
- Testing that a decode matches the stored MD5 checksum
Testing notes for FLAC
- 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.
Technical details
| File name | sample-flac-20mb.flac |
|---|---|
| Format | FLAC (Free Lossless Audio Codec) |
| Extension | .flac |
| MIME type | audio/flac |
| Size | 20,971,520 bytes (20 MB) |
| Kind | Binary |
| Signature | 66 4C 61 43 |
| SHA-256 | 113ab83100a9f2d2f03366929813b6fe1ebbaba87d0fc90e1eb9acfd65e7f9c6 |
| Created | 2026-10-23 |
| Validation | See the listed size and SHA-256. Small downloads are checked in the browser; verify streamed downloads manually. A hash match does not prove parser compatibility. |
| Preview | Available on this page |
| Source | Generated in your browser by this site's generator; not copied from elsewhere |
| Licence | Free to use, modify and redistribute (terms) |
| Category | Audio |
Check the stated structure and checksum against your application requirements. As with any download, scan the file with your own security tools before opening it. How files are made and checked
Verify your copy
This file is created in your browser, so it has no direct URL for curl or wget. The generator is designed to produce reproducible bytes. After saving, compare the checksum with the SHA-256 value above.
sha256sum sample-flac-20mb.flac # Linux
shasum -a 256 sample-flac-20mb.flac # macOSOn Windows, run Get-FileHash sample-flac-20mb.flac -Algorithm SHA256 in PowerShell. For scripts and pipelines, save the file once and keep your own copy.
Related files
Questions about this file
- Is this file exactly 20 MB?
- Yes. It is 20,971,520 bytes, which is 20 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
- What is inside the 20 MB FLAC file?
- 1,280 FLAC frames (1 min 59 s) of a synthesised musical phrase that repeats every eight seconds. The samples are stored verbatim, so the audio decodes bit for bit to the matching WAV data. 0 bytes of a standard PADDING metadata block bring the file to the exact size.
- 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.