About the SHA-3 Hash Generator
What is a SHA-3 hash?
SHA-3 is the newest member of the Secure Hash Algorithm family, standardized by NIST in 2015. Unlike SHA-1 and SHA-2, which share a common internal design, SHA-3 is built on a completely different foundation called Keccak and its "sponge" construction. This tool generates all four SHA-3 sizes, SHA3-224, SHA3-256, SHA3-384 and SHA3-512, from text or a file.
SHA-3 was chosen through a public competition specifically to provide an alternative with a different design to SHA-2, so that if a weakness were ever found in one family, the other would remain as a backup. It has no known practical attacks and is immune to the length-extension weakness that affects SHA-256 and SHA-512. This tool computes it locally in your browser with a vendored implementation of the standard, so nothing is uploaded.
How to Use This Tool
- Enter your input. Type or paste text on the Text tab, or switch to the File tab and drop in a file. The SHA-3 hash appears instantly.
- Choose the output. Use the Algorithm dropdown to choose the variant. Switch the output between hexadecimal and Base64, and pick upper or lowercase hex.
- Verify a value. Paste a hash you were given into the compare box and the tool tells you instantly whether it matches.
- Copy the result. One click copies the SHA-3 hash to your clipboard.
Common Use Cases
- Modern cryptographic hashing: a future-proof alternative to SHA-2 with a fundamentally different design.
- Standards compliance: some newer protocols and government guidance specifically call for SHA-3.
- Length-extension resistance: SHA-3 is naturally immune to the length-extension attack, unlike raw SHA-256.
- Integrity checks: verify data against a published SHA-3 digest of any size.
Frequently Asked Questions
What is the difference between SHA-2 and SHA-3?
They are unrelated internally. SHA-2 uses the Merkle-Damgard construction inherited from earlier hashes, while SHA-3 uses the Keccak sponge construction chosen through a public NIST competition. SHA-3 was standardized as a safety net: a different design means a break in one family should not affect the other. Both are secure today.
Is SHA-3 better than SHA-256?
Not better exactly, but different. SHA-3 resists length-extension attacks natively and has a fresh design, while SHA-256 is faster in software and far more widely deployed. For most purposes SHA-256 remains the default; choose SHA-3 when a specification requires it or you specifically want the alternative construction.
What is the difference between SHA-3 and Keccak?
SHA-3 is based on Keccak but NIST changed the padding rule during standardization. This means SHA3-256 and the original Keccak-256 produce different outputs for the same input. Ethereum famously uses the original Keccak-256, not the final SHA-3, which is a common source of confusion.
How long is a SHA-3 hash?
It depends on the variant: SHA3-224 is 56 hex characters, SHA3-256 is 64, SHA3-384 is 96 and SHA3-512 is 128. Switch between them with the Algorithm dropdown above.
Can SHA-3 be reversed?
No. Like every cryptographic hash it is a one-way function; the input cannot be recovered from the output except by guessing, which is infeasible for anything with real entropy.
Can I hash a file with SHA-3?
Yes. Switch to the File tab, pick your variant, and drop in any file. It is hashed entirely in your browser and matches the standard SHA-3 output.