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SHAKE256 Hash

Generate a SHAKE256 hash from any text instantly. Everything is computed in your browser, so your input never leaves your device.

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What is SHAKE256?

SHAKE256 is a cryptographic hash function from the SHA-3 family standardized by NIST (FIPS 202), offering 256 bits of security strength. Unlike traditional hash functions with fixed output sizes, SHAKE256 is an extendable-output function (XOF) that generates variable-length digests on demand, making it suitable for any application requiring flexible cryptographic hashing. This free, browser-based tool lets you compute SHAKE256 hashes instantly without uploading data or creating an account—your input never leaves your device.

How SHAKE256 works

SHAKE256 uses the Keccak sponge construction, a modern cryptographic architecture that absorbs input data and squeezes out hash output. Here's how it works:

  1. Absorption Phase: The input message is split into blocks and XORed (combined bit-by-bit) into an internal state. A permutation function is applied after each block, mixing the data thoroughly.
  2. Padding: The message is padded according to FIPS 202 specifications to maintain security properties.
  3. Squeezing Phase: Once all input is absorbed, the function produces output bits on demand. You can request any number of bytes—32 bytes (256 bits), 64 bytes (512 bits), or more—without re-processing the input.

Worked Example Structure: If you hash the text "Hello" with SHAKE256 requesting 32 bytes of output, the function absorbs "Hello", applies padding, then squeezes 32 bytes from the sponge state. The same input always produces the same output, but changing even one character produces a completely different hash—this is the avalanche effect that makes hashing secure.

How to use

  1. Type or paste your text into the input box.
  2. The SHAKE256 hash is calculated automatically as you type.
  3. Choose your output encoding (Hex or Base64) if needed.
  4. Click Copy to copy the digest to your clipboard.

Common uses

  • Creating digital signatures and verifying data authenticity without storing original content
  • Key derivation for generating cryptographic keys of custom lengths from a master secret or password
  • Ensuring file integrity by comparing hashes before and after transmission or storage
  • Building message authentication codes (MACs) to detect tampering in secure communications
  • Generating unique identifiers and cryptographic salts for password hashing and security protocols

Frequently asked questions

Is SHAKE256 secure for production use?
Yes. SHAKE256 is an official NIST standard (FIPS 202) with 256 bits of security strength and resistance to collision, preimage, and second-preimage attacks. It's suitable for high-security applications.
Can SHAKE256 hashes be reversed to get the original input?
No. SHAKE256 is a one-way cryptographic function—there's no known practical way to reverse a hash back to its input. This is why it's used for secure password storage and data verification.
What output sizes can I use?
SHAKE256 is flexible: you can request any output length from a few bytes to thousands of bytes. Common choices are 32 bytes (256 bits), 64 bytes (512 bits), or 16 bytes (128 bits) depending on your security needs.
Does this tool upload my data to a server?
No. This tool runs entirely in your browser using JavaScript. Your input is processed locally and never sent anywhere, ensuring complete privacy.
How does SHAKE256 differ from SHA-256?
SHAKE256 offers 256 bits of security like SHA-256, but it's an extendable-output function—you choose the digest length. SHA-256 always produces exactly 32 bytes; SHAKE256 produces whatever length you need.
Is SHAKE256 faster than older hash functions?
SHAKE256 is optimized for performance and can hash large inputs quickly. It's generally faster than cryptographically outdated functions like MD5 or SHA-1, though speed varies by implementation.