Keccak-256
Compute the Keccak-256 hash of any text.
Calculate Keccak-256 hashes. Free, offline, runs in your browser. Read more Show less
What is Keccak?
Keccak is a cryptographic hash based on a sponge construction, designed by Guido Bertoni, Joan Daemen, Gilles Van Assche, and Michael Peeters. It won the NIST SHA-3 competition in 2012.
Keccak as used by Ethereum is not identical to NIST SHA-3. NIST changed the padding from Keccak's original 0x01 to 0x06 before standardizing. Ethereum, Solidity, and many blockchain tools use the pre-standard Keccak with 0x01 padding. This tool implements original Keccak. If you want NIST SHA-3, use the SHA-3 tool.
FAQ
Is Keccak the same as SHA-3?
No. SHA-3 is Keccak with different padding. They produce different outputs for the same input.
Which does Ethereum use?
Ethereum's keccak256 is original Keccak-256, not NIST SHA3-256.
Why does my Ethereum hash differ from an online SHA3 calculator?
Because the other tool probably implements NIST SHA-3, which pads differently.