SHA3-256 Hash Generator
Create 256-bit SHA3-256 hashes with the Keccak sponge.
SHA3-256 · 256 bits
Result will appear here...
Keccak-256 (Ethereum) · 256 bits
Result will appear here...
SHA3-256 Hash Generator
Generate the SHA3-256 hash of text or a file with the modern SHA-3 (Keccak) algorithm. The 256-bit digest is computed in your browser and updates as you type.
About SHA3-256
SHA3-256 is part of the SHA-3 standard published by NIST in 2015 as FIPS 202. It produces a 256-bit digest and is the most widely used SHA-3 variant. Ethereum's Keccak-256 is shown alongside for comparison. SHA-3 is built on the Keccak sponge: input is absorbed into a large internal state, then the digest is squeezed out. Because of this design SHA-3 resists length-extension attacks that older Merkle-Damgård hashes are vulnerable to.
Features
- Text or file input, hashed locally up to 200 MB
- Hex, uppercase HEX, or Base64 output
- Hash each line for bulk lists
- Compare with a known hash to verify integrity
When to use SHA-3
SHA-3 is a NIST-approved secure hash and a natural companion or successor to SHA-2. Use it for signatures, integrity checks, and any protocol that calls for SHA-3. For a shared-secret signature use the HMAC Generator; to compare with the older family see the SHA256 Hash Generator.
Frequently Asked Questions
How is SHA3-256 different from SHA-2?
SHA-3 uses the Keccak sponge construction, a completely different design from SHA-2's Merkle-Damgård structure. This makes SHA-3 immune to the length-extension attacks that affect SHA-256 and SHA-512, and gives cryptographers an independent backup should SHA-2 ever be weakened.
How long is a SHA3-256 hash?
SHA3-256 outputs 256 bits, shown as 64 hexadecimal characters, uppercase, or Base64.
Is SHA-3 slower than SHA-2?
In pure software SHA-3 is often a little slower than SHA-2, but it was designed for excellent hardware performance and strong security margins. For most text and file hashing the difference is not noticeable.
Is SHA3-256 the same as Keccak?
Almost. SHA-3 uses the final NIST padding (FIPS 202), while the original Keccak submission used slightly different padding, so their outputs differ. Ethereum famously uses the original Keccak-256, which is why it is shown alongside SHA3-256 here.