100 KB BIN sample file
A BIN file of exactly 102,400 bytes. It is a valid Binary test file file, generated for this site and checked with an independent parser.
Download
sample-bin-100kb.bin
100 KB102,400 bytes
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- Type
- application/octet-stream
- SHA-256
c431baa4657f4b7a552997c3aefed445e9a3c7e486a59f9f713be213f0ee8799- Direct URL
https://sampletestfiles.com/downloads/bin/sample-bin-100kb.bin
What is in this file
102,400 pseudo-random bytes from a seeded generator, so every build of the file is identical and compression cannot shrink it.
| Content | Pseudo-random bytes |
|---|---|
| Compressible | No |
| Structure | None |
First bytes of the file
The first 64 bytes of sample-bin-100kb.bin as a hex dump: offset, bytes, then the same bytes as text.
00000000 32 89 27 61 ef 62 8b 68 4a 9f 76 74 ec e0 7e cf |2.'a.b.hJ.vt..~.|
00000010 fc 9c 01 43 fd 55 a9 e8 69 b4 04 5d 43 01 0b 87 |...C.U..i..]C...|
00000020 af 9c 68 76 7d 09 1a d3 ce 6e be 19 af d8 91 c5 |..hv}....n......|
00000030 3b 31 57 79 58 cf b9 fb 93 76 21 1d 30 a6 e2 4b |;1WyX....v!.0..K|Preview
BIN files cannot be shown in a browser. Download the file and open it with curl, wget and browser download managers.
Where 100 KB matters
A 102,400-byte file that sits exactly on the default request-body limit of Express. These are the default limits a file of this size is useful for testing:
| System | Limit | Note |
|---|---|---|
| Express body parsers | 100 KB (102,400 bytes) by default | A request body of exactly this size passes; anything larger returns 413 Payload Too Large. |
| Gmail message clipping | About 102 KB of HTML | Longer messages are truncated behind a "view entire message" link. |
| Amazon DynamoDB items | 400 KB per item | 100 KB fits; the 500 KB sample does not. |
Use this file for
- Checking email size handling
- Testing size limits precisely
- Checking resumable and chunked uploads
Testing notes for BIN
- Because application/octet-stream says nothing about content, strict upload filters reject these files. That is itself a useful test.
- A file of zeros, as produced by many quick commands, compresses to almost nothing, which makes transfers look far faster than they are.
Technical details
| File name | sample-bin-100kb.bin |
|---|---|
| Format | BIN (Binary test file) |
| Extension | .bin |
| MIME type | application/octet-stream |
| Size | 102,400 bytes (100 KB) |
| Kind | Binary |
| SHA-256 | c431baa4657f4b7a552997c3aefed445e9a3c7e486a59f9f713be213f0ee8799 |
| Created | 2026-10-10 |
| Validation | Exact size, signature bytes and structure checked when the file was generated |
| Preview | Not available for this format; details only |
| Source | Generated for this site; not copied from elsewhere |
| Licence | Free to use, modify and redistribute (terms) |
| Category | Testing |
Validated for expected format and integrity. As with any download, scan the file with your own security tools before opening it. How files are made and checked
Download from the command line and verify
Fetch the file with curl, then compare its checksum with the SHA-256 value above.
curl -o sample-bin-100kb.bin 'https://sampletestfiles.com/downloads/bin/sample-bin-100kb.bin'
sha256sum sample-bin-100kb.bin # Linux
shasum -a 256 sample-bin-100kb.bin # macOSOn Windows, run Get-FileHash sample-bin-100kb.bin -Algorithm SHA256 in PowerShell. A matching value proves that the download is complete and unaltered.
Related files
Questions about this file
- Is this file exactly 100 KB?
- Yes. It is 102,400 bytes, which is 100 KB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
- What is inside the 100 KB BIN file?
- 102,400 pseudo-random bytes from a seeded generator, so every build of the file is identical and compression cannot shrink it.
- Why not use a file full of zeros?
- Zeros compress to nearly nothing, so any compression between server and client hides the true transfer size. Random bytes do not.