Keccak-512 hash generator.

Keccak-512 is the largest output of the original Keccak sponge from the 2012 SHA-3 competition: 512 bits from a 1024-bit capacity, 256-bit security. It is SHA3-512 before NIST's padding change, so the digests differ.

Keccak is a sponge: a 1600-bit state absorbs the input in blocks, applying a 24-round permutation after each, then the digest is read from the first bits of the state. The capacity, the part of the state never output, is twice the digest size, and that is the security margin. No length-extension attack exists against it.

Yes, with the widest margin in the family and no known attack. It is also the slowest per byte, absorbing 72 bytes per permutation. Some cryptocurrencies and pre-2015 systems use it; for new work, SHA3-512 is the standard form.

Only in the padding. NIST appended two bits to the message before the Keccak padding when it standardised SHA-3 in 2015, so SHA-3 digests differ from the original Keccak's for every input. Ethereum adopted Keccak-256 before the change and kept it, so what Solidity calls sha3 or keccak256 does not match SHA3-256. This tool gives you both families; pick the one the other side uses.

Nothing leaves your browser. The hash is computed on your machine, by the browser's Web Crypto API or a WebAssembly build of the algorithm loaded on first use, and the page makes no request with your input. You can load the page, go offline and keep hashing.

Drop the file onto the input or choose it with the button, and the tool reads it in your browser and hashes the bytes. Files up to 1 GB work; past that the browser would need the whole file in memory, so the tool declines. Paste the published digest into the Verify field to compare.

Hex is the common form: 128 characters from 0 to 9 and a to f, the same value in upper or lower case. Base64 writes the same 64 bytes in fewer characters, and Base64url swaps + and / for - and _ with no padding. Switch the output and the digest is re-encoded, not recomputed.

Text is hashed as UTF-8 bytes, which is what every language and command line does by default. A trailing newline changes the digest, so `echo -n` or this tool's input, with no newline added, matches a command-line tool run on a file without one.

Turn on HMAC and enter the secret: the tool computes HMAC-Keccak-512 over the input with that key, the standard RFC 2104 construction, so the value matches what a server-side HMAC library produces. The key is hashed as UTF-8 text.

No. The Keccak-512 hash generator is free and opens without a sign-in, an account or an install.

Nothing. The Keccak-512 hash generator holds your input in the page's memory, so closing or reloading the tab clears it, and it saves nothing in this browser.

The toolbar switches to Keccak-224, Keccak-256, and Keccak-384 without leaving the page. Each one reads the same input, so you can compare digests side by side.

Keccak-512 is computed by a WebAssembly build from the hash-wasm library, which the page loads the first time you hash something and reuses after that.

Yes: the File to Keccak-512 page has the same algorithms and options and opens on the file pane. Files are read in your browser and never uploaded.

Not on its own. Keccak-512 is built to be fast, and fast hashes are cheap for an attacker to guess against. Passwords need a salted, deliberately slow hash: use Argon2id, Argon2d, and bcrypt from the hash generators, which draw a fresh random salt each time.

Closest to the Keccak-512 hash generator: File to Keccak-512, SHA3-512 hash generator, Keccak-256 hash generator, SHA-512 hash generator. Each opens on its own page, free and in the browser.

The Keccak-512 hash generator is one of 64 in its group. The group's page, /tools/hash, lists them all.

The tool is free. Its interface is built from shadcn.io's own components (Button, Input, Slider and the rest of the registry under /ui), which come in React, Vue, Svelte and Solid. Pro adds the blocks and templates for the product around it.