FIPS 202 · Keccak sponge · NIST

SHA-3 hash generator

SHA-3 is NIST's newest hash standard based on the Keccak sponge construction. Structurally different from SHA-2, providing defense-in-depth. SHA3-224 (28B), SHA3-256 (32B), SHA3-384 (48B), SHA3-512 (64B). Client-side reference.

0 chars
SHA-3 hash
 

How to use this tool

  1. Pick a digest size from the tabs at the top — SHA3-256, SHA3-512, SHA3-224, or SHA3-384.
  2. Type or paste text into the Input text box — the hash appears instantly in the SHA-3 hash display below it.
  3. Check the line under the hash for the output size, e.g. 32 bytes (256 bits).
  4. Hit Copy to copy the hash to your clipboard.
  5. Switch tabs any time — the current input is re-hashed with the new variant on the fly.
  6. Use Clear to reset the input and start over.

Why this tool is helpful

Verify data integrity

Hash a file's contents or a message to get a fixed-size fingerprint. If even one byte changes, the hash changes completely — ideal for spotting corruption or tampering.

Reference implementation for SHA-3

The browser's Web Crypto API doesn't support SHA-3. This page computes it directly in JavaScript, so you can check results without pulling in a library.

Defense in depth over SHA-2

SHA-3 uses a sponge construction instead of SHA-2's Merkle–Damgård design and is immune to length-extension attacks — a structurally different fallback.

Check against test vectors

Confirm your own SHA-3 implementation matches NIST FIPS 202 by comparing digests for the same input across all four sizes.

Choose the right digest size

Compare SHA3-224 through SHA3-512 to pick the output length that fits your storage, checksum, or signature needs.

Stay private

Everything runs in your browser. Nothing is uploaded, logged, or sent to a server — safe for sensitive payloads and keys.

FAQ

What exactly is SHA-3?

SHA-3 is NIST's latest cryptographic hash standard, defined in FIPS 202. It produces a fixed-size digest — 224, 256, 384, or 512 bits — from any input using the Keccak sponge construction.

How is SHA-3 different from SHA-2?

SHA-2 is built on the Merkle–Damgård construction, while SHA-3 uses a completely different sponge design. That structural difference makes SHA-3 immune to length-extension attacks and gives you an independent fallback if a SHA-2 weakness is ever found.

Is SHA-3 the same as Keccak?

Nearly. SHA-3 is the standardized version of the Keccak algorithm that won the NIST competition, but it uses a different padding domain (0x06), so its digests differ from the original Keccak submission (0x01). This tool computes SHA-3 per FIPS 202.

Why is the hash always the same length?

Because you choose the output size upfront. Whether you hash one word or a whole book, SHA3-256 always returns 32 bytes (64 hex characters); SHA3-512 returns 64 bytes (128 hex characters).

Is SHA-3 reversible? Can it decrypt my data?

No. A cryptographic hash is one-way — you can't recover the original input from a digest. Hashing is for integrity and fingerprinting, not encryption.

Can two different inputs produce the same hash?

In theory a collision is possible, but no practical collision is known for SHA-3. The output space is so large that finding two inputs with the same digest is computationally infeasible.

Does any of my data leave my browser?

Never. The entire hash is computed locally in JavaScript. Your input is not sent to, stored on, or logged by any server.