BLAKE2b is a fast cryptographic hash from RFC 7693, optimised for 64-bit platforms. It produces digests of any length from 1 to 64 bytes and is often faster than MD5 or SHA-1 while being far more secure.

How is BLAKE2b different from BLAKE2s?

BLAKE2b uses 64-bit words and supports up to a 512-bit (64-byte) digest, suiting 64-bit CPUs. BLAKE2s uses 32-bit words with up to a 256-bit digest and targets 8 to 32-bit platforms.

Why can I pick the output length?

BLAKE2b takes the desired digest length as a parameter mixed into its initial state, so a 32-byte digest is not simply a truncation of the 64-byte one — each length is a distinct, fully-mixed output.

No. The hash runs entirely in your browser via a pure-JavaScript BLAKE2b implementation, so the input never leaves the page.

BLAKE2b Hash Generator

What this BLAKE2b generator does

This tool computes the BLAKE2b hash of any text, with a digest length you choose from 1 to 64 bytes. BLAKE2b is a modern, high-speed cryptographic hash used in cryptocurrencies, password hashing (as the core of Argon2), file integrity, and content addressing.

How it works

BLAKE2b (RFC 7693) is built on a ChaCha-derived compression function that processes 128-byte blocks using eight 64-bit state words plus eight 64-bit initialisation-vector words. The requested digest length is folded into the first IV word as a parameter block, so each output size is a distinct hash rather than a truncation. Each block is mixed with twelve rounds of the G function — additions, XORs, and right-rotations by 32, 24, 16, and 63 bits — over a message schedule defined by the SIGMA permutation table. A final block sets the last-block flag, and the low bytes of the eight state words form the digest. Everything here runs in browser JavaScript using BigInt for the 64-bit arithmetic.

Tips and notes

The 64-byte (512-bit) output is the full-strength digest; 32 bytes is common for compact identifiers.
BLAKE2b is unkeyed in this tool, equivalent to a plain hash; keyed BLAKE2b acts as a MAC.
Example: BLAKE2b-512 of the empty string is 786a02f742015903c6c6fd852552d272912f4740e15847618a86e217f71f5419d25e1031afee585313896444934eb04b903a685b1448b755d56f701afe9be2ce.
A single changed byte changes the entire digest (avalanche effect).