Password Strength Checker

Check how strong your password is. Get a detailed analysis with entropy score and improvement tips.

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Very Weak
Score: 0 / 4 · 0 bits of entropy

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Example Strong Passwords

Click the copy button to use any of these as inspiration.

Tr0ub4dor&3!xKVery Strong
correct-horse-battery-stapleVery Strong
P@ssw0rd!2024#SecureVery Strong
X7$mK9pL2@vQ4wR8Very Strong

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Understanding Password Entropy & Cracking

Password entropy is a measure of unpredictability. It is calculated as length × log₂(character pool), where the pool grows with each character type you include (lowercase, uppercase, numbers, symbols). A password with 80 bits of entropy has 2⁸⁰ possible combinations — an astronomical number that would take even the fastest supercomputers centuries to exhaust.

How Attackers Crack Passwords

  • Brute force: Trying every possible combination. Long, diverse passwords defeat this.
  • Dictionary attacks: Using lists of common words and phrases. Avoid dictionary words.
  • Credential stuffing: Reusing leaked passwords from other breaches. Use unique passwords everywhere.
  • Social engineering: Guessing based on personal info. Avoid names, birthdays, and pet names.

Tips for Maximum Security

  • Aim for 12–16+ characters with mixed character types
  • Use a password manager to generate and store unique passwords
  • Enable two-factor authentication (2FA) on all important accounts
  • Consider passphrases — four random words can be both memorable and very strong

Frequently Asked Questions

Password entropy measures the amount of randomness or unpredictability in a password, expressed in bits. Higher entropy means more possible combinations, making the password harder to guess or crack through brute force.

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