Test files › Size ladder › 1b.bin
1 byte test file
Exactly 1 bytes of deterministic incompressible pseudo-random data.
↓ Download 1b.bin| Filename | 1b.bin |
| Format | Binary |
| Size | 1 bytes (1 bytes) |
| MIME type | application/octet-stream |
| SHA-256 | dabd3aff769f07eb2965401eb029974ebba3407afd02b26ddb564ea5f8efae72 |
What this file catchesOne byte. Catches off-by-one buffer maths and code that treats a 1-byte read as EOF.
Handle it in code
Each snippet below was run against this exact file with Python 3.14.4 and Node 24.15.0 when this page was built, and the output shown is what it printed.
Python
Verify the download against the SHA-256 published on this page. file_digest (Python 3.11+) reads in chunks, so a 250 MB file does not need 250 MB of memory.
import hashlib
with open("1b.bin", "rb") as f:
print(hashlib.file_digest(f, "sha256").hexdigest())Run against this file, it prints: dabd3aff769f07eb2965401eb029974ebba3407afd02b26ddb564ea5f8efae72
Node.js
The same in Node, streaming the file through the hash.
const crypto = require('node:crypto');
const fs = require('node:fs');
const hash = crypto.createHash('sha256');
fs.createReadStream('1b.bin')
.on('data', (chunk) => hash.update(chunk))
.on('end', () => console.log(hash.digest('hex')));Run against this file, it prints: dabd3aff769f07eb2965401eb029974ebba3407afd02b26ddb564ea5f8efae72
Related guides and tools
Large test files (1 KB to 2 GB)Large file upload testing1 GB and 2 GB test filesDownload speed test filesRange requests and resumable downloadsCheck a file's real typeVerify its SHA-256
Download & verify
curl -fsSL -o "1b.bin" "https://files.hexaqa.com/size/1b.bin"
curl -fsSL "https://files.hexaqa.com/size/1b.bin" | sha256sum
# expect: dabd3aff769f07eb2965401eb029974ebba3407afd02b26ddb564ea5f8efae72