HashTools

Password Strength Checker

See how strong your password is as you type. The password is analyzed locally and never leaves your browser.

Your password never leaves this browser tab.

Strength
  • At least 8 characters
  • At least 12 characters
  • Contains uppercase letter
  • Contains lowercase letter
  • Contains number
  • Contains special character (!@#$%^&*)
  • Not a common password
Entropy:
Estimated crack time:

What makes a password strong?

Strong passwords are long, unpredictable, and uniqueto each site. Length is the single biggest factor — adding one random character roughly multiplies the search space by the size of the alphabet you're drawing from. Mixing uppercase, lowercase, digits, and symbols adds entropy, but a short complex password is still weaker than a long passphrase.

Entropy and crack time

Entropy (measured in bits) is a rough estimate of how many guesses an attacker would need. 60 bits is a reasonable floor for general use; 80+ bits is good for high-value accounts. Crack-time estimates assume offline attacks against fast hashes at around 1010 guesses per second — slower hashes like bcrypt or Argon2 make even modest passwords much harder to crack.

Use a password manager

The best defense is to never reuse a password and to let a password manager (1Password, Bitwarden, KeePass, the one built into your browser) generate 16-character random strings for every site. You only need to remember one strong master password — and the manager handles the rest.