Keccak-512 hash
Compute a Keccak-512 digest of any file, on your device.
Runs on your device. The file is never uploaded.
Keccak-512 hash reads a file and prints 512 bits of the pre-standard Keccak function as 128 lowercase hex characters. Each file dropped returns its own digest, so a folder yields a list rather than one value. What gets hashed is the exact bytes of a file, trailing newline included, never a string you type.
Questions
How long is a Keccak-512 digest?
512 bits, printed as 128 lowercase hex characters. The tool calls hash-wasm keccak with a fixed 512-bit size and takes no options, so the same file always gives the same value. The output is two lines: the title with your file name, then the digest underneath.
Is Keccak-512 the same as SHA3-512?
No. Same permutation and same output size, different padding: SHA-3 adds a domain separation suffix that original Keccak does not. Every digest differs as a result. Use this tool for software written before FIPS 202 landed, and the SHA3-512 tool for the standard.
When would I want Keccak-512 over Keccak-256?
When something asks for it. The 512-bit output doubles the digest length and raises the birthday bound, at the cost of absorbing fewer bytes per permutation, since a larger capacity leaves a smaller rate. Keccak-256 is much more common in practice, particularly in blockchain tooling, so check what the other side expects.
Can I hash several files in one go?
Yes. Each file is hashed on its own and returns its own result, so a folder of files gives you a list of digests rather than one combined value. If you want several algorithms for a single file instead, Generate all hashes prints the whole hash-wasm table at once.
Does anything leave my device?
No. The hashing is a WebAssembly build of hash-wasm running in a Web Worker in this tab. Nothing is uploaded, there is no account and there is no server side, and the page keeps working with the network switched off once you have visited the site.