Password Hashing Best Practices Every Developer Should Follow

Storing passwords in plaintext is a breach waiting to happen. Hashing turns a password into a fixed-length digest that cannot be reversed, so even a leaked database doesn’t hand attackers the keys to your users’ accounts. But not all hashing is equal — the choices you make decide how well your users survive a breach.

Here are the practices that matter most when you implement password hashing.

Use a Purpose-Built Algorithm

General-purpose hashes like MD5 and SHA-256 are fast — and speed is exactly what attackers want. Use algorithms designed to be slow and memory-hungry instead.

• Argon2id — OWASP’s first choice; tune memory and time costs.
• bcrypt — battle-tested; use a cost factor of 12 or higher.
• scrypt — a strong option when memory hardness matters most.

Salt Everything, Automatically

A unique random salt per password defeats rainbow tables and stops identical passwords from producing identical hashes. Modern libraries generate and store salts for you — never roll your own crypto.

Add a Pepper and Tune Your Costs

An application-wide secret pepper, stored outside the database, adds defense in depth. Revisit your cost parameters yearly as hardware improves, and rehash credentials on login whenever you upgrade algorithms.

Finally, never log passwords, enforce rate limits, and offer MFA so hashing isn’t your only line of defense.