SHA3 Hash Generator

What is SHA-3?

SHA-3 is the hash family NIST standardized in FIPS 202, offering fixed digests of 224, 256, 384, or 512 bits. The number in the name is the output size.

Choose a size, then hash typed text or uploaded files. Each result includes the raw digest bytes and the lowercase hexadecimal text.

Why a second standard family

SHA-3 exists as insurance rather than as a replacement. SHA-2 is not broken, but it shares an internal structure with MD5 and SHA-1, both of which fell to collision attacks. Standardizing a family built on an unrelated construction means a future break in one lineage does not leave everyone without options.

That independence is the reason to reach for it. If a design needs to survive a weakness being found in SHA-2, or a specification simply names SHA-3, this is the tool. For general hashing where nothing dictates the choice, SHA-2 remains more widely implemented.

Are there alternatives?

SHA256 and SHA512 are the SHA-2 equivalents and appear in far more libraries and protocols. BLAKE3 and BLAKE2b are considerably faster than either family.

SHAKE Hash comes from the same FIPS 202 standard but produces output of any length you ask for rather than a fixed size. Keccak Hash implements the original submission, which is not the same thing.

Fun facts and more info

SHA-3 and Keccak are not interchangeable. SHA-3 adds domain-separation padding that the original Keccak design does not, so SHA3-256 and Keccak-256 return different digests for identical input. Use Keccak Hash only when a protocol explicitly calls for original Keccak.

The construction behind SHA-3 is not vulnerable to length extension, unlike SHA-256 and SHA-512, so a bare SHA-3 digest avoids that particular trap. It remains one way and not encryption, and plain SHA-3 is no substitute for a password hashing function.