Hash Identifier

About this calculator

Cryptographic and password hashes carry no explicit label saying which algorithm produced them, but their length and character set are usually a strong tell: an MD5 digest is always 32 hex characters (128 bits), SHA-1 is 40 hex characters (160 bits), SHA-256 is 64 hex characters (256 bits), and password-hashing schemes like bcrypt encode their own prefix, such as $2a$, $2b$ or $2y$, followed by a work-factor and a base64-style salt-plus-hash string rather than plain hex.

Penetration testers and digital forensics investigators use this kind of pattern-matching — the same logic tools like hashcat and John the Ripper apply when auto-detecting a hash mode — as the first step before attempting to crack or verify a hash, since picking the wrong algorithm makes every subsequent attempt fail no matter how strong the cracking dictionary is.