BLAKE2b

Calculate BLAKE2b hashes or keyed MACs from text and encoded bytes with selectable digest length, key encoding, Hex, and Base64 output. Read more

What is BLAKE2b?

BLAKE2b is the BLAKE2 variant optimized for 64-bit platforms. It accepts a digest length from 1 to 512 bits in this tool and can run either as an unkeyed cryptographic hash or in BLAKE2’s built-in keyed mode. Use BLAKE2s when compatibility requires the smaller 32-bit-oriented variant, or BLAKE3 when a protocol specifically calls for BLAKE3.

How to use this hash calculator

  1. Enter text or encoded bytes in the Input panel.
  2. Select the input encoding that describes those bytes.
  3. Choose the output length and output encoding.
  4. Leave Key empty for an ordinary BLAKE2b digest, or enter the exact secret key and key encoding required by a keyed protocol.

The digest length is part of the BLAKE2 computation. A 256-bit BLAKE2b digest is not obtained by calculating BLAKE2b-512 and simply truncating its displayed Hex string.

Result example

With a 512-bit output and no key, UTF-8 abc produces ba80a53f981c4d0d6a2797b69f12f6e94c212f14685ac4b74b12bb6fdbffa2d17d87c5392aab792dc252d5de4533cc9518d38aa8dbf1925ab92386edd4009923. Entering 616263 as Hex produces the same result because it represents the same three bytes.

Important limitations

An unkeyed BLAKE2b digest can detect changes only when the expected digest is trusted. It does not identify who supplied the message. Keyed BLAKE2 can act as a MAC, but both parties must use the same secret key, key encoding, digest length, and message bytes. BLAKE2b is also not a password-hashing function; use a password-specific construction such as Argon2 when password guessing resistance is required.

RFC 7693 specifies BLAKE2b, BLAKE2s, their variable digest lengths, and built-in keyed operation.

Frequently asked questions

Why does my result differ from another tool?

Check whether the other implementation uses BLAKE2b rather than BLAKE2s, then compare the input bytes, digest length, key bytes, and output encoding. A keyed result never matches the unkeyed digest of the same message.

Can I use the result to verify data?

Use the BLAKE2b File Hash tool to hash local files or accessible URLs without first converting their bytes to text.

Input
Output
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Hash
Key