What is a hash?
A hash function turns any input into a fixed-length fingerprint. The same input always gives the same hash, but changing a single character changes the whole result. Hashes are used to check file integrity, build cache keys and compare data without storing it.
Which algorithm should I use?
- SHA-256 — the modern default for checksums and signatures.
- SHA-512 — longer output, often faster on 64-bit CPUs.
- SHA-1 — legacy only (Git still uses it). It is broken for security purposes.
Can I hash passwords with this?
Do not store passwords as plain SHA hashes. Use a slow, salted password hash such as Argon2, bcrypt or scrypt on your server instead.