How is SHA3 different from SHA-2?

SHA3 (standardised as FIPS 202) is built on the Keccak sponge construction, a completely different internal design from SHA-2 (SHA-256, SHA-512). It was chosen as a structural backup so a weakness in one family would not affect the other.

Is SHA3-256 the same as Keccak-256?

No — they differ by one padding byte. FIPS-standard SHA3-256 uses the domain-separation byte 0x06, while the original Keccak-256 (used by Ethereum) uses 0x01. This tool produces the standard SHA3-256.

No. The hash is computed entirely in your browser in pure JavaScript — nothing is sent over the network.

SHA3-256 Hash Generator

SHA3-256 hash generator (FIPS 202)

SHA3-256 is the 256-bit member of the SHA-3 family standardised in FIPS 202. Unlike SHA-2, it is built on the Keccak sponge construction, giving it a fundamentally different internal design — a deliberate hedge against any future weakness in the SHA-2 family.

Type or paste your text and the 64-character hex SHA3-256 hash appears instantly. Note this is the FIPS-standard SHA3-256 (padding byte 0x06), not the Ethereum-style Keccak-256 variant. Everything runs locally in your browser.