Hash Generator (MD5, SHA-1, SHA-256, SHA-512)

What is a hash function?

A cryptographic hash function takes any input and produces a fixed-length "fingerprint" called a digest. The same input always yields the same digest, but even a one-character change produces a completely different result, and you cannot reverse a digest back to the original input. Hashes are used for verifying file integrity, indexing data, and — combined with proper techniques — storing passwords.

The algorithms here

• MD5 (128-bit) — fast and still common for non-security checksums, but cryptographically broken: attackers can craft collisions. Never use it for signatures or password storage.
• SHA-1 (160-bit) — also broken for collision resistance (the SHAttered attack, 2017). Deprecated for security; fine only for legacy compatibility checks.
• SHA-256 / SHA-384 / SHA-512 — the SHA-2 family, currently recommended. SHA-256 is the default choice for integrity and digital signatures; SHA-512 is faster on 64-bit hardware for large inputs.

Common uses

• Verifying that a downloaded file matches the publisher's checksum.
• Generating a stable cache key or content-addressed identifier.
• Detecting whether two pieces of data are identical without comparing them byte by byte.
• Building the inner primitive for HMAC message authentication.

Hashing is not encryption — and not enough for passwords

A hash is one-way: there is no key and no "unhash" operation. That also means a plain hash is the wrong tool for storing passwords. Because hashing is fast, attackers can try billions of guesses per second against a leaked database. To store passwords you need a slow, salted algorithm such as bcrypt, scrypt or Argon2 — not a bare SHA-256. Use this tool for integrity and checksums, not for hashing user passwords directly.

Why run it in the browser?

Every digest on this page is computed locally with the Web Crypto API (and a built-in MD5 implementation, since Web Crypto omits the broken MD5). Your input never leaves the page, so you can safely hash internal data. For keyed authentication where both integrity and authenticity matter, use our HMAC generator instead.