SHA-3 Hash Generator
Compute the NIST FIPS-202 SHA-3 hash (SHA3-256, SHA3-384, or SHA3-512) of any text. This is the standardized SHA-3, which differs from the original Keccak used by Ethereum. Runs entirely in your browser, no server, no sign-up.
About this tool
This SHA-3 hash generator computes the FIPS-202 SHA-3 digest of any text right in your browser. The hashing runs locally in WebAssembly — your input is never uploaded to a server, which makes it safe for keys, tokens, and other sensitive strings.
A hash is a fixed-length fingerprint of its input. The same text always produces the same digest, but the digest cannot be reversed back into the original — so hashes are ideal for verifying that data has not changed, fingerprinting content, and deriving identifiers.
SHA-3 vs. Keccak — they are not the same
This tool implements FIPS-202 SHA-3, the version NIST standardized after the
hash competition, which uses 0x06 multi-rate padding. The original Keccak
submission used 0x01 padding. Because the padding differs, SHA3-256 and
Keccak-256 produce completely different digests for the same input — they are
not interchangeable.
- Use SHA-3 (this tool) when you need the NIST standard (FIPS-202).
- Use Keccak (in the Keccak Hash Generator) when you need the hash that Ethereum and the wider EVM ecosystem use.
Supported variants
- SHA3-256 (default) — a 256-bit / 32-byte digest.
- SHA3-384 — a 384-bit / 48-byte digest.
- SHA3-512 — a 512-bit / 64-byte digest.
Options
- Variant — choose SHA3-256, SHA3-384, or SHA3-512.
- Interpret input as — hash the text as plain UTF-8 (default), or decode it
from hex (a leading
0xis accepted) or base64 first so you can hash existing raw bytes such as a key or a file's contents. - Output format — return the digest as hex (default) or as base64.
- Uppercase hex — emit the hex digest in uppercase.
Notes
- A hash is a one-way function: a digest cannot be reversed back into the original text.
- SHA-3 is built on the Keccak sponge construction but is not related to the older SHA-1 or SHA-2 families by design — it was selected as a structurally different backup standard.
- For the original Keccak (Keccak-256 / Keccak-512) used by Ethereum, use the Keccak Hash Generator tool instead.
FAQ
Why doesn't my SHA3-256 match a Keccak-256 tool?
Because they aren't the same algorithm. This tool implements FIPS-202
SHA-3, which uses 0x06 multi-rate padding; the original Keccak (what
Ethereum uses) uses 0x01 padding. The differing padding means the two
produce completely different digests for identical input — use the Keccak Hash
Generator when you need the Ethereum-compatible value.
Can I hash raw bytes instead of a text string?
Yes. Set Interpret input as to hex or base64 and the tool decodes
the input to raw bytes before hashing — handy for hashing a key, a file's
contents or another digest. A leading 0x on hex input is accepted; invalid
hex or base64 is reported as an error rather than hashed literally.
What's the difference between the three variants?
Digest size: SHA3-256 produces 32 bytes, SHA3-384 48 bytes and SHA3-512 64 bytes. Larger digests give a wider security margin at slightly more output length; SHA3-256 is the default and the most common choice for checksums and fingerprints.
Does the uppercase option change the hash itself?
No — it only affects how the same digest is displayed as hex (base64
output ignores it). A1B2... and a1b2... are the identical SHA-3 hash. All
hashing runs in your browser, so the text you enter is never uploaded.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool sha3-hash "Hello, World!"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/sha3-hash/?text=Hello%2C%20World%21&algorithm=sha3-256&input_encoding=text&output_format=hex&uppercase=trueMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.