Free BIN sample files
Pseudo-random bytes with no structure. The right file for measuring transfer speed and size limits. Download valid BIN test files in 10 exact sizes, from 1 KB to 10 MB, each with a checksum.
- Extension
- .bin
- MIME type
- application/octet-stream
- Kind
- Binary
- Category
- Testing
BIN files by size
Every file below is a valid Binary test file file of exactly the stated size. Open a file's page for its checksum and contents. BIN files cannot be displayed by a browser, so their pages show the file's details instead of a preview.
| File | Size | Contents | Download |
|---|---|---|---|
| 1 KB BIN samplesample-bin-1kb.bin | 1 KB1,024 bytes | Pseudo-random bytes | Download BIN |
| 5 KB BIN samplesample-bin-5kb.bin | 5 KB5,120 bytes | Pseudo-random bytes | Download BIN |
| 10 KB BIN samplesample-bin-10kb.bin | 10 KB10,240 bytes | Pseudo-random bytes | Download BIN |
| 25 KB BIN samplesample-bin-25kb.bin | 25 KB25,600 bytes | Pseudo-random bytes | Download BIN |
| 50 KB BIN samplesample-bin-50kb.bin | 50 KB51,200 bytes | Pseudo-random bytes | Download BIN |
| 100 KB BIN samplesample-bin-100kb.bin | 100 KB102,400 bytes | Pseudo-random bytes | Download BIN |
| 500 KB BIN samplesample-bin-500kb.bin | 500 KB512,000 bytes | Pseudo-random bytes | Download BIN |
| 1 MB BIN samplesample-bin-1mb.bin | 1 MB1,048,576 bytes | Pseudo-random bytes | Download BIN |
| 5 MB BIN samplesample-bin-5mb.bin | 5 MB5,242,880 bytes | Pseudo-random bytes | Download BIN |
| 10 MB BIN samplesample-bin-10mb.bin | 10 MB10,485,760 bytes | Pseudo-random bytes | Download BIN |
What is a BIN file?
A .bin file here is simply a block of pseudo-random bytes of an exact length. It has no format, no header and no meaning.
Random data cannot be compressed, so the number of bytes sent over the network equals the file size. That makes these files the honest choice for speed tests and for checking limits on servers that compress responses.
How to recognise a BIN file
No signature bytes. BIN files are identified by parsing their content.
| Extension | .bin |
|---|---|
| MIME type | application/octet-stream |
| Structure | None |
| Compressibility | None; gzip and Brotli cannot shrink it |
| Generation | Seeded pseudo-random generator, identical in every build |
| Signature | None |
What to test for
These are the behaviours that most often go wrong when software handles BIN files.
- A file of zeros, as produced by many quick commands, compresses to almost nothing, which makes transfers look far faster than they are.
- Because application/octet-stream says nothing about content, strict upload filters reject these files. That is itself a useful test.
Strengths of BIN
- Cannot be compressed, so transfer measurements are honest.
- No format to validate, which isolates size and transport behaviour.
Limitations of BIN
- Rejected by upload forms that check content type.
- Says nothing about how an application handles a real document.
Typical uses of BIN test files
- Measuring download and upload throughput
- Testing size limits precisely
- Checking resumable and chunked uploads
- Verifying checksums after transfer
Software that opens BIN
- curl, wget and browser download managers
- Hex editors
- Any upload form that accepts arbitrary files
Specifications
Related
BIN sample files: questions
- Is a .bin sample safe to download?
- Yes. It is inert data: random bytes that are not executable and have no structure for any program to interpret.
- 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.
- What is the MIME type of a BIN file?
- The MIME type is application/octet-stream. The file extension is .bin.
- Is a sample BIN file the same as a dummy or example BIN file?
- Yes. Sample, test, dummy and example BIN files are different names for the same thing: a BIN 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 BIN file.