What Is SHA-256?

A clear introduction to SHA-256, what a cryptographic hash does and common uses of SHA-256.

SHA-256 is a cryptographic hash function

SHA-256 takes input data and produces a fixed-length hash value. Small changes to the input should produce dramatically different output, making hashes useful for integrity checking and other cryptographic applications.

The output has a fixed size

The original input can be short or long, but SHA-256 produces a result of the same length. This makes the output useful as a compact fingerprint of data.

Common uses

SHA-256 can be used in integrity systems, digital signatures and other cryptographic protocols. A published hash can help someone verify whether a downloaded file matches the expected data.

SHA-256 is not a password storage solution by itself

This distinction is important. SHA-256 is designed to be fast. Password storage benefits from specialised algorithms that deliberately make repeated guessing more expensive and include appropriate salting.

Try it locally

The HashMyPass SHA-256 tool can demonstrate how changing the input changes the resulting hash. It is useful for learning and basic checksum-style experimentation.