SHA-3 Hash Calculator
Calculate SHA-3 hashes of any text using the four standardized variants: SHA3-224, SHA3-256, SHA3-384 and SHA3-512. Enter text and select Calculate SHA-3 hashes to generate all four hexadecimal digests.
What is SHA-3?
SHA-3 (Secure Hash Algorithm 3) is a family of cryptographic hash functions standardized by NIST in 2015 as FIPS 202. It is based on Keccak, selected in a public competition. SHA-3 offers a different internal design from SHA-2; SHA-2 remains secure and is not made obsolete by SHA-3.
Like other cryptographic hashes, SHA-3 converts input data into a fixed-length digest. A small change to the input will generally produce a very different result. Hashes can help verify data integrity, but they cannot be used to reconstruct the original input.
How does SHA-3 work?
SHA-3 uses a sponge construction. It absorbs input bytes into a 1600-bit state, repeatedly applies the Keccak-f[1600] permutation, and then squeezes out the requested digest. Unlike SHA-2, the standardized SHA-3 hash functions are not susceptible to the classic length-extension attack.
This calculator converts text to UTF-8 and calculates all four SHA-3 variants locally in your browser. It does not upload the text for hashing.
SHA-3 variants
| Algorithm | Output size | Hex characters | Absorption rate |
|---|---|---|---|
| SHA3-224 | 224 bits | 56 | 1152 bits |
| SHA3-256 | 256 bits | 64 | 1088 bits |
| SHA3-384 | 384 bits | 96 | 832 bits |
| SHA3-512 | 512 bits | 128 | 576 bits |
All four variants use the SHA-3 standard, but they produce different digests even for the same input.
SHA-3 vs. Keccak-256
SHA3-256 and Keccak-256 are not interchangeable. The NIST SHA-3 standard uses different domain-separation padding from the earlier Keccak implementation. Ethereum uses Keccak-256, not NIST SHA3-256. This calculator implements the standardized SHA-3 variants (with the SHA-3 domain-separation byte 0x06).
How to use this calculator
- Enter or paste text in the Input text field.
- Select Calculate SHA-3 hashes.
- Copy the SHA3-224, SHA3-256, SHA3-384 or SHA3-512 result using its individual copy button.
Frequently asked questions
Can SHA-3 hashes be reversed?
No. SHA-3 is a one-way cryptographic hash function. Although common inputs may be guessed and checked, a hash cannot feasibly be inverted to recover arbitrary original text.
Is SHA-3 more secure than SHA-2?
Both SHA-2 and SHA-3 are considered secure for general-purpose cryptographic hashing. SHA-3 provides an alternative construction, rather than a mandatory replacement for SHA-2.
Should I use SHA-3 to store passwords?
No. SHA-3 is designed for efficient hashing, not password storage. Use a dedicated, configurable password-hashing function such as Argon2id, scrypt or bcrypt instead.
Why does my SHA3-256 hash differ from an Ethereum Keccak-256 hash?
They use different domain-separation padding. This calculator implements NIST SHA3-256, not Ethereum Keccak-256.
Why do two SHA-3 calculators produce different results?
Check the selected variant, exact input bytes, whitespace and text encoding. Also verify whether the other calculator uses standardized SHA-3 or the original Keccak algorithm.
Related tools
- SHA-2 hash calculator — Calculate four SHA-2 variants.
- SHA-256 hash calculator — Generate 256-bit SHA-2 hashes.
- SHA-384 hash calculator — Generate 384-bit SHA-2 hashes.
- SHA-512 hash calculator — Generate 512-bit SHA-2 hashes.
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