SHA512 Hash Generator

What the SHA-512 generator does

This produces the SHA-512 hash of your text, a 128-character hex fingerprint, the longest of the common SHA digests. Type or paste your text, press Convert, and copy or download the result.

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 SHA-512 hash appears, ready to Copy or Download.

What makes SHA-512 different

SHA-512 is the heavyweight of the SHA-2 family. Its fingerprint is 512 bits, which is 128 hex characters, double the length of SHA-256's. It is built on 64-bit internal arithmetic rather than the 32-bit arithmetic SHA-256 uses, and it works through your data in larger chunks. The longer output gives it a bigger safety margin, with even more room before a collision could be imagined than SHA-256 already has, which is part of why it is chosen where a generous margin is wanted.

Often faster than SHA-256, oddly enough

Here is the part that surprises people. You would expect the bigger hash to be the slower one, but on a modern computer it often is not. Because SHA-512 works in 64-bit pieces, and today's processors are 64-bit, it can chew through more data per step, and on that hardware it frequently runs faster than SHA-256, not slower. The picture flips on older 32-bit hardware, where SHA-256 has the edge. So "longer" does not automatically mean "heavier" here, and on the machine in front of you SHA-512 may well be the quicker of the two.

The engine behind a whole branch

SHA-512 is not just one hash, it is the foundation for several. The SHA-384 you may have seen is SHA-512 with a shorter output and different seed values, and the same is true of two less common cousins, SHA-512/224 and SHA-512/256, which take the SHA-512 engine and trim its result to 224 or 256 bits. So when you use this tool you are using the base that an entire side of the family is built on.

The library doing the work

The hashing is handled by js-sha512, a small JavaScript library implementing the 64-bit SHA-2 engine. Your text is read as UTF-8 bytes and run through the algorithm in your browser, with the 128-character hex result handed back.

Questions people ask

Is SHA-512 more secure than SHA-256?

It has a larger margin thanks to its longer output, and is a fine choice where that is wanted. For most everyday purposes SHA-256 is already more than strong enough, and both are considered secure.

Is SHA-512 slower because it is bigger?

Not necessarily. On modern 64-bit machines it often runs faster than SHA-256, because it processes data in 64-bit chunks. On older 32-bit hardware SHA-256 tends to be faster.

When should I use it?

When you want the longest standard SHA digest and a bigger safety margin, or when you are matching a system that already uses SHA-512. Otherwise SHA-256 is the common pick.

Can I reverse a SHA-512 hash?

No. A SHA-512 hash is a one-way fingerprint, not a container, so the original text is not recoverable from it. The SHA-256 page goes into the detail.

References

1. National Institute of Standards and Technology (2015). FIPS PUB 180-4: Secure Hash Standard (SHS). https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf
2. js-sha512, a SHA-512 and SHA-384 implementation for JavaScript (npm package). https://www.npmjs.com/package/js-sha512