Password Strength Guide

Password strength is mostly about length, randomness, and uniqueness. A “complex” password that is short or reused can still be weak in practice.

1) What makes a password strong?

  • Length: longer is better (12+ is a baseline; 16–24 is excellent).
  • Uniqueness: one password per site prevents “credential stuffing”.
  • Randomness: avoid predictable patterns and common substitutions.

2) How password meters estimate strength

Meters typically estimate guessability using heuristics: character sets, length, and pattern detection. Some also estimate crack time using assumed attacker speeds. Treat it as guidance, not a guarantee.

3) Practical checklist

  • Use a password manager to generate and store long random passwords.
  • Enable 2FA (prefer passkeys or authenticator apps over SMS).
  • Rotate passwords after breaches and stop reusing passwords.

Try the tools

FAQ

What matters most for password strength?

Length and uniqueness matter most. Use long, unique passwords per site.

Is a password strength meter always accurate?

It is an estimate. Different meters use different assumptions and models.

Should I reuse a strong password?

No. Reuse is one of the biggest risks. Use a password manager instead.