What is a hash?
A hash function turns any input into a fixed-length “fingerprint”. The same input always gives the same hash, and even a one-character change produces a completely different result. Hashes are used to verify downloads, detect duplicate files and store data integrity checks.
Which algorithm should I use?
- SHA-256 — the modern default for checksums and integrity checks.
- SHA-512 / SHA-384 — longer variants of SHA-2.
- MD5 and SHA-1 — still common for file checksums, but broken for security: never use them for passwords or signatures.
Should I hash passwords with this?
No. Passwords should be stored with slow, salted algorithms such as bcrypt, scrypt or Argon2 — not plain SHA or MD5.