What is SHA-256 and when should you use it?
A practical, non-confusing explanation of SHA-256, how it differs from encryption, and where it’s used in real systems.
SHA-256 in one sentence
SHA-256 is a one-way cryptographic hash function used to generate a fixed-length fingerprint of data.
Hashing vs encryption vs encoding
- Hashing: one-way, used for integrity checks
- Encryption: reversible with a key, used for secrecy
- Encoding: reversible without a key, used for formatting/transport
When you should use SHA-256
- File integrity verification (downloads, backups)
- Digital signatures (as part of signing workflows)
- Tamper detection (logs, configuration snapshots)
When you should NOT use SHA-256 alone
- Password storage: use a password hashing algorithm like bcrypt/argon2/scrypt
- If you need reversible secrecy: use encryption (AES, etc.)
Try it
Use the SHA-256 tool on your site:
/tools/hash-generator/sha256
FAQ
Is SHA-256 reversible?
No. You cannot “decrypt” a hash.
Can two different files have the same SHA-256?
In theory yes (collision), but it’s computationally infeasible for practical scenarios.