SHA3-256 Hash Generator Online, Free and Private
Compute the SHA3-256 hash of text or a file in your browser, in hex or Base64, and compare it with an expected value. Other SHA-3 sizes are one click away. Nothing is uploaded.
This is the digest of the empty input.
SHA3-256
About the SHA3-256 hash
This page computes the SHA3-256 hash of text or a file in your browser. SHA3-256 is the 256-bit member of SHA-3, the hash family NIST standardised in 2015 as FIPS 202. Its digest is 32 bytes, written as 64 hexadecimal characters. Unlike SHA-256, which belongs to the older SHA-2 family, SHA-3 is built on the Keccak sponge construction, a completely different design chosen in a public competition. Type or paste text, or choose a file of up to 50 MB, and the digest appears at once. Nothing is uploaded, and your data never leaves your device.
How to get a SHA3-256 hash
Steps
- Type or paste the text, or press Choose file for a file of up to 50 MB.
- SHA3-256 is already selected in the Algorithm list. Switch to SHA3-224, SHA3-384 or SHA3-512 there if you need another size.
- Turn on Upper case or Base64 to match the format you are comparing against, then press Copy SHA3-256.
- Paste a published value into Compare with to check it; the page reads Matches or No match.
Privacy
The hash is computed by code running on this page. Your text and files are never uploaded to our servers and are forgotten when you close the tab.
SHA-3 in practice
When to use it
SHA3-256 offers the same 128-bit collision resistance as SHA-256 and no practical attack against either is known. Choose SHA-3 when a protocol or specification names it, when you want a hash from a different design family than SHA-2 as a safety margin, or when you need a hash that is not vulnerable to length-extension attacks, which affect SHA-256 and SHA-512 when they are misused as a keyed MAC.
Not the same as Keccak-256
Ethereum's keccak256 is not SHA3-256. Ethereum adopted Keccak before NIST finalised the standard, and FIPS 202 changed the padding byte. The two functions give completely different digests for the same input. For Ethereum, Solidity and smart-contract work, use the Keccak-256 hash page instead.
Checking the output
- SHA3-256 of the empty input is
a7ffc6f8bf1ed76651c14756a061d662f580ff4de43b49fa82d80a4b80f8434a, the value you see before typing. - On a terminal,
printf 'text' | openssl dgst -sha3-256gives the same value;echoadds a newline and changes the digest. - Text is hashed as its UTF-8 bytes.
Related tools
The full Hash Calculator offers 32 algorithms, including SHAKE128 and SHAKE256, the extendable-output members of SHA-3. For the six common digests at once, MD5 to SHA-512, see the Hash Generator, and the SHA-256 hash page if you need the SHA-2 equivalent.
Open-source credits
SHA3-256 and the rest of the SHA-3 family are computed by @noble/hashes by Paul Miller, MIT licence, an audited implementation of FIPS 202.