SHA3-256 Hash Generator

Generate SHA3-256 hashes using the Keccak sponge construction. The latest NIST standard, independent from SHA-2.

Enter text and click Generate to create a SHA3-256 hash

Other Hash Algorithms

What is SHA3-256?

SHA-3 (Secure Hash Algorithm 3) is the latest member of the Secure Hash Algorithm family, standardized by NIST in 2015. Based on the Keccak algorithm, it uses a fundamentally different construction (sponge) than SHA-2, providing algorithmic diversity. SHA3-256 produces a 256-bit hash value.

How SHA3-256 Works

SHA-3 uses a sponge construction with a 1600-bit state (a 5×5 matrix of 64-bit words). Data is absorbed into the state through XOR operations, then squeezed out. The permutation function Keccak-f[1600] applies 24 rounds of five operations: θ (theta), ρ (rho), π (pi), χ (chi), and ι (iota).

Output

64 hex characters (256 bits)

Year

2015

Status

✓ Secure

Common Use Cases

  • Post-quantum security hedging
  • Ethereum (Keccak-256, a SHA-3 variant)
  • Diversifying hash function dependencies
  • Random number generation (sponge-based PRNG)
  • Future-proof cryptographic applications

Security Considerations

SHA3-256 provides full 256-bit security with 128 bits of collision resistance. Its sponge construction is fundamentally different from SHA-2's Merkle-Damgård construction, meaning an attack on SHA-2 would not affect SHA-3. This makes SHA-3 an ideal backup hash function.

SHA3-256 vs Other Algorithms

SHA3-256 provides equivalent security to SHA-256 but is typically 2-3x slower in software implementations. Hardware implementations can be very efficient. The key advantage is algorithmic diversity — if SHA-2 is ever broken, SHA-3 remains secure. Ethereum uses Keccak-256, a pre-standardization variant of SHA-3.

Frequently Asked Questions

What is SHA-3?
SHA-3 is the latest NIST hash standard, based on the Keccak algorithm. It uses a sponge construction fundamentally different from SHA-2, providing algorithmic diversity as a hedge against future SHA-2 vulnerabilities.
Is SHA-3 better than SHA-256?
Neither is strictly "better." SHA-256 is faster in most software implementations and is more widely supported. SHA-3 offers a different internal construction, meaning it would remain secure even if SHA-2 were broken. Both provide equivalent 256-bit security.
Does Ethereum use SHA-3?
Ethereum uses Keccak-256, which is based on the same algorithm but was finalized before NIST made minor changes to create SHA-3. Keccak-256 and SHA3-256 produce different outputs for the same input.
How long is a SHA3-256 hash?
A SHA3-256 hash is 256 bits (32 bytes), displayed as a 64-character hexadecimal string — the same length as SHA-256.
What is the sponge construction?
The sponge construction absorbs input data into a large state through XOR operations, then squeezes out the hash. Unlike Merkle-Damgård (used by SHA-2), it can produce variable-length output and has different security properties.
Is SHA-3 quantum-resistant?
SHA3-256 provides 128 bits of post-quantum collision resistance (Grover's algorithm halves the effective security). For maximum quantum resistance, use SHA3-512.