Hash Identifier
Paste an unknown hash and get a ranked list of likely algorithms based on its length, character set, and prefix.
How hash identification works
Cryptographic hashes have a fixed output size and a predictable character set, which is enough to narrow the algorithm down to a short list. A 32-character hex string is almost always MD5 (but could be NTLM or MD4); a 64-character hex string is most often SHA-256 but could be BLAKE2s or SHA3-256. Some algorithms use modular crypt format (MCF) prefixes — $2b$ for bcrypt, $argon2id$ for Argon2 — that identify them unambiguously.
Why this is useful
Hash identification is a common first step in CTF challenges, malware analysis, and legacy-system debugging. When you find a hash in a database dump or a configuration file with no accompanying schema, knowing the algorithm tells you which cracking tool to point at it (hashcat's -m mode numbers, John the Ripper format strings) and what to expect about its security properties.
Limitations
Length-based identification cannot tell some algorithms apart — MD5 and MD4 are both 128-bit; SHA-256, BLAKE2s, and SHA3-256 are all 256-bit. Treat “Likely” as a best guess and “Possible” as a hint, not a verdict. Truncated or Base64-encoded hashes are especially ambiguous.