SHA3-512 Hash Generator

What the SHA3-512 generator does

This produces the SHA3-512 hash of your text, a 128-character hex fingerprint, the longest in the SHA-3 family. Type or paste your text, press Convert, and copy or download the result. Like every hash it is one-way, so the result cannot be turned back into your text.

It runs in your browser, so nothing you enter is uploaded.

How to use it

1. Enter your text. Type or paste it, or upload a plain text file.
2. Press Convert. The 128-character SHA3-512 hash appears, ready to Copy or Download.

The biggest SHA-3 digest

SHA3-512 produces the longest fingerprint of the four SHA-3 hashes, 512 bits or 128 hex characters, which gives it the largest safety margin of the family. It is built on the same sponge construction as the rest of SHA-3, the design that sets the whole family apart from the older SHA hashes and is explained in full on the SHA3-256 page. You would choose the 512 size when you want the most generous margin SHA-3 offers, or to match a system specified around a 512-bit digest.

Why the bigger SHA-3 is the slower one

Here is a quirk that runs the opposite way to SHA-2, and it comes straight from how the sponge works. In the sponge, the internal pool is a fixed size, and the longer the hash you want out of it, the more of that pool has to be reserved for security, which leaves less room to soak up your data on each pass. Less room per pass means more passes, so a bigger SHA-3 hash is actually the slower one to compute. SHA3-512 is therefore slower than SHA3-256, not faster. That is worth keeping in mind, because in the SHA-2 family the reverse is often true, where SHA-512 can outrun SHA-256 on modern hardware. The two families behave differently, so the instinct from one does not carry to the other.

The library doing the work

The hashing is handled by js-sha3, a small JavaScript library implementing the SHA-3 family. Your text is read as UTF-8 bytes and run through the sponge in your browser, with the 128-character hex result handed back.

Questions people ask

Is SHA3-512 more secure than the smaller SHA-3 sizes?

It has a larger margin thanks to its longer output, and is a fine choice where that is wanted. The smaller sizes are already strong, so for most purposes the choice comes down to the digest length a system needs.

Is it slower than SHA3-256?

Yes. Because of how the sponge works, a longer SHA-3 hash leaves less room to absorb data per pass, so SHA3-512 computes more slowly than SHA3-256.

Can I reverse a SHA3-512 hash?

No. It is one-way, so the original text cannot be recovered. The SHA-256 page explains why no hash can be reversed.

References

1. National Institute of Standards and Technology (2015). FIPS PUB 202: SHA-3 Standard: Permutation-Based Hash and Extendable-Output Functions. https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf
2. js-sha3, a SHA-3 and Keccak implementation for JavaScript (npm package). https://www.npmjs.com/package/js-sha3