SHA-256 Generator
SHA-256 hash of text in hex or Base64, compared with a checksum when you paste one.
SHA-3 Generator
A SHA3 generator for SHA3-224, SHA3-256, SHA3-384, and SHA3-512, plus Keccak-256 for Ethereum work. SHA3-256 is selected when the page opens.
Hashed in your browser. Your text is not uploaded.
Hashed as UTF-8. A trailing space or line break changes the hash.
How to use the SHA-3 Generator
- Paste the string you want a SHA-3 digest of. The default
abcshows the FIPS 202 test result. - Pick the size under Algorithms. SHA3-256 is ticked by default; tick SHA3-224, SHA3-384, or SHA3-512 for the other sizes, or Keccak-256 for an Ethereum-style hash.
- Choose hex or Base64 and copy the row you need.
- Paste an expected value into Compare with to check it against every ticked algorithm.
How SHA-3 works
SHA-3 comes from Keccak, the design that won NIST's hash competition in 2012. NIST published it as FIPS 202 in 2015. It does not use the block chaining of MD5 and SHA-2. Instead it keeps a 1600-bit state, absorbs the input into part of it, scrambles the whole state 24 times per block, and then squeezes the output out. This is called a sponge.
The number in the name is the output size in bits. Larger sizes take in fewer input bytes per block, so SHA3-512 is the slowest of the four. Browsers have no built-in SHA-3, so the page loads a WebAssembly hasher from this site and runs it on your device.
Examples
| Algorithm | Hash of abc |
|---|---|
| SHA3-224 | e642824c3f8cf24ad09234ee7d3c766fc9a3a5168d0c94ad73b46fdf |
| SHA3-256 | 3a985da74fe225b2045c172d6bd390bd855f086e3e9d525b46bfe24511431532 |
| Keccak-256 | 4e03657aea45a94fc7d47ba826c8d667c0d1e6e33a64a036ec44f58fa12d6c45 |
SHA3-256 and Keccak-256 differ even though both are 256-bit Keccak. FIPS 202 changed one padding byte before publishing the standard, and Ethereum had already adopted the original version.
SHA-3 sizes compared
| Algorithm | Output | Hex length | Input per block |
|---|---|---|---|
| SHA3-224 | 224 bits | 56 | 144 bytes |
| SHA3-256 | 256 bits | 64 | 136 bytes |
| SHA3-384 | 384 bits | 96 | 104 bytes |
| SHA3-512 | 512 bits | 128 | 72 bytes |
| Keccak-256 | 256 bits | 64 | 136 bytes |
Limitations
- The SHAKE128 and SHAKE256 functions from FIPS 202, which give output of any length, are not included.
- An Ethereum address uses Keccak-256 of the public key bytes, not of text. Hashing a typed hex string here gives the hash of those characters, not of the bytes they spell.
- The first SHA-3 or Keccak hash on a page takes a moment while the WebAssembly hasher loads.
- Input is text from the box. Command line tools such as
openssl dgst -sha3-256cover files.
Frequently asked questions
Is SHA-3 better than SHA-256?
Neither has a known weakness. SHA-3 is a different design, so it stays safe if a flaw is ever found in SHA-2. SHA-256 is faster in most software and far more widely supported.
Is Keccak-256 the same as SHA3-256?
No. They share the algorithm but use a different padding byte, so the same input gives different hashes. Ethereum and Solidity's keccak256 use Keccak-256.
Which SHA-3 size should I pick?
SHA3-256 for general checksums and IDs. Choose a larger size only when a standard or a partner system asks for it.
Related tools
Often used together with SHA-3 Generator.
SHA-512 Generator
SHA-512 hash of text as 128 hex characters or Base64.
Hash Generator
Hashes text with ten algorithms and compares the result with an expected hash.