BLAKE2s is the 32-bit variant of BLAKE2 from RFC 7693, tuned for 8 to 32-bit platforms and embedded systems. It produces digests from 1 to 32 bytes and is fast and secure.

How is BLAKE2s different from BLAKE2b?

BLAKE2s uses 32-bit words, 64-byte blocks, 10 rounds, and a maximum 256-bit digest. BLAKE2b uses 64-bit words, 128-byte blocks, 12 rounds, and up to a 512-bit digest, which is faster on 64-bit CPUs.

Why can I choose the output length?

The requested digest length is mixed into BLAKE2s's initial state, so a 16-byte digest is a distinct, fully-mixed hash rather than a truncation of the 32-byte output.

Is my text sent anywhere?

No. The hash is computed entirely in your browser with a pure-JavaScript BLAKE2s implementation, so the input never leaves the page.

BLAKE2s Hash Generator

What this BLAKE2s generator does

This tool computes the BLAKE2s hash of any text, with a digest length you choose from 1 to 32 bytes. BLAKE2s is the compact, 32-bit member of the BLAKE2 family, well suited to embedded and constrained environments while remaining fast and secure on any platform.

How it works

BLAKE2s (RFC 7693) processes 64-byte blocks using eight 32-bit state words and eight 32-bit initialisation-vector words. The chosen digest length is folded into the first IV word as a parameter block, so each output size is its own hash. Each block runs ten rounds of the G mixing function — 32-bit additions, XORs, and right-rotations by 16, 12, 8, and 7 bits — driven by the SIGMA message-permutation schedule. The final block sets the last-block flag, and the low bytes of the eight state words form the digest. All arithmetic is kept to 32 bits using unsigned masking in browser JavaScript.

Tips and notes

BLAKE2s tops out at a 256-bit (32-byte) digest; use BLAKE2b when you need 512 bits.
The rotation constants (16, 12, 8, 7) differ from BLAKE2b’s (32, 24, 16, 63) — that is the core word-size difference.
Example: BLAKE2s-256 of the empty string is 69217a3079908094e11121d042354a7c1f55b6482ca1a51e1b250dfd1ed0eef9.
A single changed byte changes the entire digest (avalanche effect).