SHA224 Hash Generator

What is SHA-224?

SHA-224 is the shortest member of the SHA-2 family standardized in NIST FIPS 180-4. It always produces 224 bits: 28 bytes, or 56 hexadecimal characters.

Feed it typed text or uploaded files, one digest per input, returned as raw bytes and lowercase hexadecimal.

Why a 224-bit digest exists

It is SHA-256's machinery with a different starting state and a shorter result. The compression function, the block size, and the word size are all shared, so it costs the same to compute as SHA-256 while returning four fewer bytes.

That combination is only worth having when something else fixes the size for you. A protocol field, a legacy record layout, or a matching security level with a 112-bit target are the usual reasons. When nothing constrains the length, the extra four bytes of SHA-256 are free and more widely supported.

Are there alternatives?

SHA256 is the default choice and the one other systems expect. SHA512 offers SHA-512/224, which lands on the same digest size through a different route and runs faster on 64-bit hardware.

Those two are not interchangeable with this one. SHA-224 and SHA-512/224 produce different digests for the same input despite the matching length, so match whichever the other system specifies. None of them store passwords: that needs Argon2id Hash Generator.

Fun facts and more info

Because the output is a truncation of a larger internal state, SHA-224 does not hand an attacker enough information for the length-extension trick that works against full SHA-256. That is a side effect of the shorter output rather than a design goal.

Like any hash it runs one way only, and the input cannot be recovered from the digest. Fifty-six hexadecimal characters is an unusual enough length to be a useful clue: find one in a log and SHA-224 and SHA-512/224 are your two candidates.