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SHAKE256 hash calculator

SHAKE256 is an extendable-output function (XOF) from the SHA-3 family: instead of a fixed digest, you ask for exactly as many bits as you need, with up to 256-bit security.

SHAKE256 at a glance

Outputany length you choose
Rate / capacity1088 / 512 bits
Securityup to 256 bits (collision: min(d/2, 256))
StandardNIST FIPS 202 (2015)
SiblingSHAKE128: rate 1344, up to 128-bit security

Where it is used

SHAKE256 is used in Ed448 signatures (RFC 8032), in ML-DSA and ML-KEM, and in the SHAKE variants of SLH-DSA. Set the output length above to the size your protocol needs.

Known answers

SHAKE256 with a 512-bit output:

InputDigest (hex)
"" (empty)46b9dd2b0ba88d13233b3feb743eeb243fcd52ea62b81b82b50c27646ed5762fd75dc4ddd8c0f200cb05019d67b592f6fc821c49479ab48640292eacb3b7c4be
"abc"483366601360a8771c6863080cc4114d8db44530f8f1e1ee4f94ea37e78b5739d5a15bef186a5386c75744c0527e1faa9f8726e462a12a4feb06bd8801e751e4
"hello world"369771bb2cb9d2b04c1d54cca487e372d9f187f73f7ba3f65b95c8ee7798c527f4f3c2d55c2d46a29f2e945d469c3df27853a8735271f5cc2d9e889544357116

In code

import hashlib
hashlib.shake_256(b"hello world").hexdigest(64)  # 64 bytes = 512 bits

More languages: SHA-3 code examples. Other calculators: SHA3-256 · SHA3-512 · Keccak-256.

Frequently asked

Is the SHAKE256 calculator private?

Yes. The hash is computed in your browser; nothing you type or drop is uploaded.

What is the SHAKE256 of an empty string?

SHAKE256 with a 512-bit output of "" = 46b9dd2b0ba88d13233b3feb743eeb243fcd52ea62b81b82b50c27646ed5762fd75dc4ddd8c0f200cb05019d67b592f6fc821c49479ab48640292eacb3b7c4be

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