Keccak/SHA-3 Hash Generator
Generate SHA3-224/256/384/512 and Keccak-256 (Ethereum) hashes of text or files in your browser.
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What is Keccak/SHA-3 Hash Generator?
The Keccak/SHA-3 Hash Generator computes SHA3-224, SHA3-256, SHA3-384, SHA3-512, Keccak-256 and Keccak-512 hashes directly in your browser. SHA-3 is the NIST hash standard (FIPS 202) built on the Keccak sponge function, and Keccak-256 is the original variant that Ethereum uses for addresses and smart contracts. Everything runs client-side with a pure-JavaScript implementation verified against official NIST test vectors.
Key Benefits
- Nothing leaves your device — text and files are hashed locally
- All six SHA-3 and Keccak variants in one tool
- Live hashing as you type, with instant variant switching
- Verified against official NIST FIPS 202 test vectors
- Works offline as a static page with no server dependency
Common Use Cases
- •Verifying Ethereum addresses and computing keccak256() values for Solidity
- •Generating checksums for files before download or backup
- •Comparing digests to detect data tampering
- •Learning how sponge-construction hashing differs from SHA-2
- •Preparing content hashes for signatures and commit-style verification
How to Use the Keccak/SHA-3 Hash Generator
- Choose a variant: Pick SHA3-256 for standards work or Keccak-256 for Ethereum addresses and Solidity. SHA3-224/384/512 and Keccak-512 are also available.
- Enter text or select a file: Type or paste text — the hash updates live as you type. Or switch to the File tab and pick a file up to 20 MB.
- Read the digest: The hexadecimal digest appears below the input along with its length. Switching variants instantly re-hashes the same input.
- Copy the hash: Click the copy button next to Generate to copy the digest to your clipboard, ready to paste into documentation or code.
Key Features
- All six variants: SHA3-224, SHA3-256, SHA3-384, SHA3-512, Keccak-256, Keccak-512
- Hash text with live preview or files up to 20 MB
- Ethereum-ready Keccak-256 for addresses and Solidity keccak256()
- 100% in-browser: no uploads, no API, works offline
- One-click copy of the hexadecimal digest
- Accessible UI with screen-reader announcements
Frequently Asked Questions
What is the difference between SHA3-256 and Keccak-256?
They use the same Keccak-f[1600] permutation but different padding: Keccak-256 (the original submission) appends 0x01 while FIPS 202 SHA3-256 appends 0x06. The result is two completely different digests for the same input. Ethereum uses Keccak-256.
Which variant does Ethereum use?
Ethereum and all EVM chains use Keccak-256 — the pre-standardization variant — for address derivation, transaction hashes, Solidity keccak256() and EIP-712 signatures. Choose the Keccak-256 option in this tool for any Ethereum-related work.
Are my files or text uploaded anywhere?
No. The Keccak permutation runs entirely in JavaScript in your browser. Nothing is sent to any server — you can even disconnect from the internet after the page loads and the tool keeps working.
Is SHA-3 more secure than SHA-256?
SHA-3 and SHA-2 (which includes SHA-256) are both currently secure. SHA-3 uses a completely different sponge construction, so it provides insurance: a future attack on SHA-2 would not apply to SHA-3, and vice versa. For new designs, SHA3-256 is a solid choice.
Can I hash large files?
Yes, files up to 20 MB are supported in File mode. Text input is limited to 5 MB. Hashing a 20 MB file takes a few seconds because everything is computed locally in your browser.