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.

How long is a SHA3-256 hash?

It is 256 bits, displayed as 64 hexadecimal characters, the same output length as SHA-256.

Yes. SHA3-256 is a current NIST-standard cryptographic hash with no known practical weaknesses. As with any general-purpose hash, store passwords with a dedicated function like bcrypt or Argon2 rather than a raw SHA3 hash.

When should I choose SHA3-256 over SHA-256?

Both are secure and the same length. Choose SHA3-256 when you specifically need a SHA-3 family hash, want structural diversity from SHA-2, or a protocol or standard mandates FIPS 202.

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, a fundamentally different internal design — a deliberate hedge against any future weakness in the SHA-2 family. This tool produces it for developers needing a FIPS-standard SHA3 digest.

How it works

The tool encodes your text as UTF-8 and runs a pure-JavaScript Keccak sponge: it absorbs the input into a fixed internal state, then squeezes out a 256-bit result, shown as 64 hexadecimal characters. SHA3-256 uses the FIPS domain-separation padding byte 0x06. The important distinction is from Keccak-256 (used by Ethereum), which uses padding byte 0x01 and therefore gives a different hash for the same input. This generator produces the standard SHA3-256, not Keccak-256.

Example

Input	SHA3-256 (64 hex characters)
(empty)	a7ffc6f8bf1ed76651c14756a061d662f580ff4de43b49fa82d80a4b80f8434a

Like any hash it is one-way: the same input always gives the same digest, and any change to the input changes the whole output. Everything runs locally in your browser, with nothing sent over the network.