SHA-3 Hash Generator

Generate a SHA-3 cryptographic hash of any text, right in your browser. Pick an output size — SHA3-224, SHA3-256, SHA3-384, or SHA3-512 — choose hexadecimal or base64 encoding, and optionally paste an expected hash to verify a match. Nothing you type ever leaves your device: the digest is computed locally in JavaScript.

What is SHA-3?

SHA-3 (Secure Hash Algorithm 3) is the newest member of the SHA family, standardized by NIST in 2015 as FIPS 202. It is built on the Keccak sponge construction, which is structurally very different from the Merkle–Damgård design behind MD5, SHA-1, and the SHA-2 family. That difference is the point: SHA-3 was selected precisely so the world would have a strong, standardized alternative that does not share SHA-2's internal structure, in case a future attack ever weakens SHA-2.

A hash function turns a message of any length into a fixed-size digest. The same input always produces the same output, a single changed character produces a completely different digest, and the process cannot be reversed to recover the original message. The number in the variant name is the digest length in bits: SHA3-256 produces a 256-bit (64 hex-character) digest, SHA3-512 a 512-bit (128 hex-character) one.

How to use this tool

1. Type or paste your message into the Message to hash box.
2. Choose the SHA-3 output size (SHA3-256 is a solid default).
3. Pick the output format — hexadecimal (lower or upper case) or base64.
4. The hash appears instantly. Use the copy or download buttons to save it.
5. To verify a file or a hash someone gave you, paste it into Expected hash — the tool reports whether it matches (hex comparison is case-insensitive; base64 is case-sensitive).

SHA-3 vs. Keccak

This is the most common point of confusion. The original Keccak submission and the finalized FIPS-202 SHA-3 use different padding, so they produce different digests for the same input. Many older libraries (including the widely used crypto-js) shipped a "SHA3" function that actually implements the pre-standard Keccak padding — the same variant used by Ethereum's keccak256. This tool implements true FIPS-202 SHA-3, so its output matches the official NIST test vectors — for example, SHA3-256 of abc is 3a985da74fe225b2045c172d6bd390bd855f086e3e9d525b46bfe24511431532. If you need the Ethereum/Keccak variant instead, be aware the two are not interchangeable.

Is SHA-3 more secure than SHA-256?

For practical purposes both are considered secure today; neither has a known collision. SHA-3 offers a different underlying construction as insurance, and its sponge design resists length-extension attacks that affect SHA-2. For most applications SHA-256 remains the common default; choose SHA-3 when a specification requires it or when you want structural diversity from SHA-2.

Can I hash a password with this?

Plain SHA-3 is not suitable for storing passwords — it is far too fast, which helps attackers brute-force it. Use a purpose-built password hash such as bcrypt, scrypt, or Argon2 instead. SHA-3 is the right tool for checksums, digital signatures, integrity verification, and deriving fixed-length identifiers.