SHA3-256 Hash Generator
Turn any text into its 64-character SHA3-256 hash instantly.
How to use the SHA3-256 Hash Generator
- Type or paste your text in the box.
- The SHA3-256 hash appears as you type.
- Click Copy to grab the result.
About the SHA3-256 Hash Generator
SHA3-256 produces a 256-bit digest written as 64 hexadecimal characters, and it is the SHA-3 variant most people reach for — it matches the familiar output width of SHA-256, so it slots into existing designs without changing field sizes. It comes from Keccak, designed by Guido Bertoni, Joan Daemen, Michaël Peeters and Gilles Van Assche, which won the NIST SHA-3 competition in 2012 and became FIPS 202 in 2015.
The important thing to understand about SHA-3 is why it exists. It was not a rescue mission: SHA-2 was never broken and SHA-256 is still perfectly secure and still the more common choice in practice. After collision attacks demolished MD5 and then SHA-1 — all of which share the same Merkle–Damgård lineage — NIST wanted a standard hash built on genuinely different mathematics, so that one clever insight could not take out every approved algorithm at once. Keccak’s “sponge construction” absorbs input into a large internal state and then squeezes the digest back out, which has nothing structurally in common with how SHA-2 works. It also means SHA3-256 is immune to the length-extension attack that SHA-256 needs HMAC to work around.
One point that trips people up constantly: SHA3-256 and “Keccak-256” are not the same thing. During standardisation NIST changed the padding rule, so the FIPS 202 SHA3-256 you get here produces a different digest from the original Keccak-256 submission. Ethereum adopted the original Keccak-256 before FIPS 202 was finalised, which is why Ethereum tooling hashes do not match SHA3-256 output. In software SHA-3 is generally slower than SHA-2, though it is efficient in hardware; if raw speed on a CPU is what matters and you do not need the different structure, SHA-2 is the pragmatic pick.
Frequently asked questions
Can I decrypt or reverse a SHA3-256 hash?
No. Hashing is one-way — the original text is not stored inside the hash, so there is nothing to decrypt. Sites offering SHA-3 “decryption” are simply looking your hash up in a table of previously hashed common words.
Is SHA3-256 better than SHA-256?
Neither is broken, so “better” depends on what you need. SHA-256 is faster in software and far more widely supported; SHA3-256 is structurally different and is immune to length-extension attacks. Both give 128-bit collision resistance.
Why does my Ethereum hash not match this tool?
Ethereum uses the original Keccak-256, which was submitted before NIST changed the padding rule during standardisation. This tool implements the standardised FIPS 202 SHA3-256, so the two produce different digests for the same input.
Why is my SHA3-256 hash always 64 characters?
SHA3-256 always outputs 256 bits, and each hex character represents 4 bits, so every hash is exactly 64 characters regardless of input length.
Is my text sent anywhere?
Your text is sent to our server to be hashed, because browsers cannot compute SHA-3. It is hashed and immediately discarded — never logged, never stored.