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SHA3 Hash Calculator

SHA3-224/256/384/512, Keccak-256 and SHAKE — all in your browser

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CHUNKY
MUNSTER

SHA3 Hash Reference

What is SHA3?

SHA3 (Secure Hash Algorithm 3) was standardised by NIST in 2015. It is based on the Keccak sponge construction — structurally different from SHA1 and SHA2's Merkle-Damgård design, making it resistant to length-extension attacks.

SHA3 vs Keccak — what's the difference?

Keccak was the competition winner. NIST modified the padding scheme slightly when standardising it as SHA3. Keccak-256 and SHA3-256 give different outputs for the same input. Ethereum uses Keccak-256 (not NIST SHA3).

What is SHAKE?

SHAKE128 and SHAKE256 are extendable-output functions (XOFs). Unlike fixed-output hashes you can request any number of output bits. SHAKE128 gives 128-bit security; SHAKE256 gives 256-bit security at any output length.

SHA3 or SHA2 — which should I use?

Both are secure and widely trusted. SHA2 has broader platform support. SHA3 is preferred when you need algorithmic diversity, resistance to length-extension attacks without HMAC, or when standards require it explicitly.