Cryptography Tools
SHAKE256 Generator
Generate SHAKE256 output from UTF-8 text at a selected length of 16, 32, 64, or 128 bytes.
✓ Every tool runs in your browser. We do not upload your input or output.
Keyboard shortcuts
Ctrl/⌘ + Enter: process
Ctrl/⌘ + Shift + F: full screen
Esc: exit full screen
Ctrl/⌘ + F in editor: search
How to use
- Paste the exact text to process.
- Select the byte length required by your specification.
- Run SHAKE256 and inspect the hexadecimal output.
- Copy the value and note the output length for another implementation.
Examples
Produce a 64-byte test value
A different output length changes the displayed number of bytes.
Release manifest v3.1
128 hexadecimal characters at 64 bytes
Record both variant and length
SHAKE256 belongs to the SHA-3 family of extendable-output functions. Its name does not fix how many output bytes you receive. Choose a length that matches your protocol or test vector; the default on this page is 64 bytes. The output uses lowercase hexadecimal characters, with two characters for each byte. If another tool appears to disagree, confirm that it requested the same number of bytes before comparing the strings.
The source text is encoded as UTF-8 exactly as entered, including spaces and newlines. The computation runs in a local Web Worker, so the site does not receive the text. SHAKE256 is distinct from SHA3-512 and SHAKE128 even when their displayed hex lengths happen to match. An unkeyed output can summarize content but does not authenticate a sender. For the formal function definition and terminology, consult the NIST SHA-3 standard.
A 16-byte output is offered for inspection, but applications should follow the length and security requirements of their protocol. Do not choose a short output merely to save characters in a security-sensitive setting. This page performs the computation; it does not select safe protocol parameters for you.
Frequently asked questions
Is SHAKE256 the same as SHA3-512?
No. SHAKE256 is extendable-output; SHA3-512 has a fixed 512-bit output.
Does 256 mean 256 output bits?
No. The name identifies the SHAKE variant; output length is selected separately.
Can another tool reproduce the value?
Yes, if it uses SHAKE256 with identical input bytes and requested length.
Why are lengths limited here?
The interface bounds output to 16, 32, 64, or 128 bytes for convenient comparison.