BLAKE2b Hash Generator

What is BLAKE2b?

BLAKE2b is a cryptographic hash tuned for 64-bit platforms, producing anything from 1 to 64 bytes. The default here is 64 bytes, the standard BLAKE2b-512 result, with 16, 32, and 48 also offered.

Hash typed text or uploaded files and get back raw digest bytes plus lowercase hexadecimal.

Why the length is not a truncation

This is the part that catches people. The output length you choose is mixed into the BLAKE2 calculation itself, so a 32-byte BLAKE2b digest is not the first 32 bytes of the 64-byte one. They are unrelated values over the same input.

The practical consequence: match the length the other system uses, exactly. Getting it wrong does not give you a shorter version of the right answer, it gives you a completely different digest, and the mismatch looks like corrupted data rather than a configuration error.

Are there alternatives?

BLAKE2s is the sibling built for 32-bit and smaller platforms, capped at 32 bytes. BLAKE3 supersedes both for raw speed and adds unlimited extendable output.

SHA512 and SHA256 are slower but more widely implemented, which is often the deciding factor. For password storage use Argon2id Hash Generator, and for keyed authentication that other systems can verify, HMAC Generator.

Fun facts and more info

Shorter outputs give less collision and preimage resistance, so treat the length as a security parameter and not a formatting preference.

It runs one way and is not encryption, and plain BLAKE2b is not a password hashing function.

BLAKE2b was designed to beat MD5 on speed while being a genuinely secure hash, which is most of why it spread through package managers, filesystems, and cryptographic libraries. Being faster than a broken algorithm removed the last excuse for using the broken one.