แฮช SHA-256

The empty string has a single, well-known SHA-256 digest. You will see this constant in logs, caches, CDNs and storage systems as the fingerprint of empty content.

Input  : (empty)
SHA-256: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855

Classic test vector for SHA-256 implementations. Many cryptographic libraries ship a self-test that hashes this exact string.

Input  : hello
SHA-256: 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824

The most commonly cited SHA-256 example on the web. Used in tutorials, RFCs and Wikipedia to illustrate the algorithm's output.

Input  : hello world
SHA-256: b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9

Production-grade SHA-256 in 4 lines using the browser's native Web Crypto API. No external libraries, no uploads, audited native implementation.

const buf = new TextEncoder().encode('hello')
const hash = await crypto.subtle.digest('SHA-256', buf)
const hex = [...new Uint8Array(hash)]
  .map(b => b.toString(16).padStart(2, '0'))
  .join('')
console.log(hex)
// 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824

Standard-library SHA-256 hash with hex output. Works in Python 3.6+.

import hashlib
print(hashlib.sha256(b'hello').hexdigest())
# 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824

Verify a downloaded file with one shell command. macOS and Linux ship sha256sum (or shasum -a 256 on macOS) by default.

$ echo -n 'hello' | sha256sum
2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824  -

$ sha256sum installer.dmg
e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855  installer.dmg