b2KIT

SHA-3 Hash Generator

Generate SHA-3 (Keccak) hash values in SHA3-224, SHA3-256, SHA3-384, and SHA3-512 variants.

Tested tool guide Tested browser tools Checked August 16, 2026

What SHA-3 Hash Generator does, with a checked example

Paste any text and this tool returns its SHA-3 fingerprint as a fixed-length hexadecimal string, in any of the four NIST-standardized sizes: SHA3-224, SHA3-256, SHA3-384, and SHA3-512. The computation runs entirely in your browser over the exact characters you type, so the same input always produces the same digest. What surprises most people: SHA3-256 is not the same as Keccak-256, the variant Ethereum uses. The two differ in padding: SHA-3 appends a domain-separation byte of 0x06, Keccak-256 one of 0x01. That split was settled during the SHA-3 competition, before NIST's standard, so they produce different digests for identical input.

Worked example

A concrete input and expected output from the current implementation.

Input

abc

Expected output

3a985da74fe225b2045c172d6bd390bd855f086e3e9d525b46bfe24511431532

abc is one of the official test strings in FIPS 202; its SHA3-256 digest is fixed at 64 hex characters (256 bits). Any conforming SHA-3 implementation must return this exact value.

How the result is produced

1

Sponge construction

SHA-3 is a sponge function built on the Keccak-f[1600] permutation. Your input is padded with multi-rate padding, whose domain-separation byte distinguishes SHA-3 from the original Keccak submission, then absorbed into the sponge in rate-sized blocks; the digest is squeezed out afterwards. Each variant fixes a different capacity, which determines how much input each block can absorb.

2

Fixed-size hex output

The variant dropdown sets the digest size: 224, 256, 384, or 512 bits, shown as 56, 64, 96, or 128 lowercase hexadecimal characters. Output length never depends on input length, and any change to the input, including a trailing space or newline, changes the whole digest. Hashing the same text twice yields the identical string, which is what makes a hash usable as a fingerprint.

Good uses

  • Verifying a downloaded file or published text against a SHA3-256 checksum from its author; if the digest you compute differs, the bytes you have are not the ones the checksum describes.
  • Cross-checking a hash that your own script, pipeline, or database generated, to confirm the implementation is correct before you rely on it downstream.
  • Recording a fingerprint of a message or record now and later proving an unseen copy matches it exactly, without ever exchanging the content itself.

Limits and checks

  • SHA3-256 is not Keccak-256. Ethereum and several libraries label the original Keccak function 'keccak256'; because the two pad differently - SHA-3 appends 0x06, Keccak-256 0x01 - they give different digests for the same input. An expected value produced by a Keccak tool will never match this page.
  • The tool hashes the literal characters you type, encoded as UTF-8 text. The word 'abc' is not the same input as the hex string 616263, and a checksum from a file must be computed over the exact same bytes, including any trailing newline. Paste the text exactly as the reference was made.
  • A hash is not encryption and not a password hash. The digest cannot be reversed, but short, guessable inputs can be brute-forced, and unsalted SHA-3 is far too fast to protect passwords. For credential storage, use a dedicated key-derivation function such as Argon2 or bcrypt.

Common questions

Can this tool reverse the hash and show me my original text?

No. SHA-3 is one-way: the digest contains no recoverable trace of the input, and nothing on the page, or anywhere else, can invert it. If your input is short and guessable, someone could hash candidates until one matches, so a hash of a weak input is not a secret.

Why does my SHA3-256 not match the Keccak-256 hash from my Ethereum tool?

Because they are different algorithms. Keccak won NIST's hash competition, but the two use different padding - SHA-3 appends 0x06, the original Keccak 0x01 - which changes every digest. Ethereum kept the original padding, so 'keccak256' and SHA3-256 share structure but never agree on a value for the same input.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

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