Hash Generator — MD5, SHA-1, SHA-256, SHA-384 & SHA-512

Which algorithm, and whether it is still safe

"Broken" here means a collision can be produced deliberately — two different inputs with the same hash. It does not mean the hash can be reversed; none of these can be.

SHA-3 and BLAKE2/BLAKE3 are also current and secure. They are not offered here because SubtleCrypto does not implement them natively, and a JavaScript implementation would be far slower on large files.

Do not hash passwords with these

What these hashes are genuinely good for

• Download verification —Hash a file you downloaded and compare it to the publisher’s stated checksum. This detects corruption reliably, and tampering as long as you obtained the checksum over a channel the attacker did not control.
• Deduplication —Identical content produces an identical hash, so hashing is how storage systems detect duplicate files without comparing them byte by byte.
• Content addressing —Git names every object by its hash; container registries and content-addressed stores do the same. The hash is the identifier.
• Cache keys and ETags —A hash of the content changes exactly when the content changes, which is precisely the property a cache key needs.
• HMAC signatures —Webhook signing uses HMAC-SHA256 — a keyed construction built on the hash. Note that HMAC is not the same as hashing the secret together with the body, and the difference is security-relevant.

Computing the same hashes in code

# macOS and Linux
shasum -a 256 file.iso
md5sum file.iso            # Linux
md5 file.iso               # macOS

# Windows PowerShell
Get-FileHash file.iso -Algorithm SHA256

const data = new TextEncoder().encode('hello');
const digest = await crypto.subtle.digest('SHA-256', data);
const hex = [...new Uint8Array(digest)]
  .map(b => b.toString(16).padStart(2, '0'))
  .join('');

import hashlib

h = hashlib.sha256()
with open('file.iso', 'rb') as f:
    # Read in chunks so memory use stays flat
    for chunk in iter(lambda: f.read(1024 * 1024), b''):
        h.update(chunk)
print(h.hexdigest())

# NOT hashlib. Use a password KDF.
from argon2 import PasswordHasher

ph = PasswordHasher()
stored = ph.hash("correct horse battery staple")
ph.verify(stored, "correct horse battery staple")   # raises on mismatch