BLAKE2 and BLAKE3 Hash Generator

SHA-2 has been the default hash for years, but a newer family has become popular where speed and flexibility matter. BLAKE2 was released in 2012 as a faster successor to BLAKE, one of the finalists in the SHA-3 competition, and BLAKE3, published in 2020, builds on it with a tree structure that makes hashing parallel. Argon2 and WireGuard are built on BLAKE2, and BLAKE3 is used by a growing number of file and backup tools. This page lets you compute BLAKE3, BLAKE2b and BLAKE2s digests, with the options most online hashers leave out.

The three algorithms

BLAKE2b is tuned for 64-bit processors and gives up to 64 bytes of output. BLAKE2s is meant for 32-bit and small devices and gives up to 32 bytes. BLAKE3 has a single design with no variants, is much faster on large inputs because it splits data into chunks that are hashed independently and combined in a tree, and can produce output of any length. All three are fast on a laptop; the browser version here is slower than native code but fine for small inputs and files of a few megabytes.

A worked example

Press Sample to hash the three letters abc. With BLAKE3 and the default length of 32 bytes the page shows 6437b3ac38465133ffb63b75273a8db548c558465d79db03fd359c6cd5bd9d85 in hex and ZDezrDhGUTP/tjt1JzqNtUjFWEZdedsD/TWcbNW9nYU= in Base64. That is the same value the reference implementation prints for abc, which makes it a handy self-test for your own code.

Output length

The “Output length in bytes” field takes 1 to 64 bytes for BLAKE2b, 1 to 32 for BLAKE2s and up to 1024 for BLAKE3. Shortening is not truncation for BLAKE2: the requested length is part of the algorithm’s setup, so a 16-byte BLAKE2b digest is unrelated to the first 16 bytes of the 64-byte one. BLAKE3 is an extendable-output function, so asking for 64 bytes returns a longer stream whose first 32 bytes are the same as the default digest. That property is useful for generating key material, though a 16-byte result still carries at most 64 bits of collision resistance.

Keyed hashing and key derivation

Give BLAKE3 a 32-byte key, as text or hex, and the digest becomes a message authentication code: only holders of the key can produce it. Choose the key derivation option instead and give a context string, and the input is treated as secret key material from which a key bound to that context is derived. BLAKE2b accepts an optional key of up to 64 bytes and BLAKE2s up to 32 bytes. The page rejects a BLAKE3 key of the wrong length with a clear message instead of padding it.

Limits

Fast hashes are the wrong tool for storing passwords, because speed helps an attacker who guesses billions of candidates; use Argon2id, scrypt or bcrypt for that. The page offers the main parameters only: it does not expose BLAKE2 salt, personalisation or tree-hashing settings. Large files are read into memory.

Related tools

• SHA-3 and Keccak Hash Generator covers the other modern hash family.
• HMAC Generator is the standard way to make keyed digests with SHA-2.
• PBKDF2 and HKDF Calculator derives keys from passwords or key material.
• Hash Generator computes common hashes such as SHA-256 and MD5.