SHA-3 & Keccak-256 Hash Generator
The newest NIST hash standard, plus Ethereum's Keccak-256.
About this tool
SHA-3 (2015) is the newest member of the Secure Hash Algorithm family, standardized by NIST after a public competition won by the Keccak design. It uses a completely different internal structure (a sponge construction) from SHA-2, so a future break of SHA-2 would not affect it — which is why it exists as a hedge, not a replacement.
This tool computes all SHA-3 digest sizes at once, plus Keccak-256 — the original, pre-standardization variant that Ethereum adopted and still uses for addresses and hashing. All digests are computed by the audited @noble/hashes library in your browser.
Like everything on encrypt.tools, this runs entirely in your browser — nothing you enter is transmitted or stored.
Frequently asked questions about SHA-3 / Keccak
What is the difference between SHA-3 and Keccak-256?+
Keccak-256 is the original algorithm submitted to the NIST competition; SHA-3 is the final standard, which changed the padding rule. They produce different outputs for the same input. Ethereum uses the pre-standard Keccak-256, which is why blockchain tools need it specifically.
Is SHA-3 better than SHA-256?+
Not stronger in practice — both are secure. SHA-3 uses a fundamentally different construction (sponge vs. Merkle–Damgård), so it serves as a backup in case a structural weakness is ever found in SHA-2. Most systems still use SHA-256 for speed and compatibility.
Which one does Ethereum use?+
Ethereum uses Keccak-256 (the pre-standardization variant), not the final SHA3-256. This tool outputs both so you can get correct hashes for Ethereum addresses and Solidity's keccak256().