Password Strength Checker
Check how strong your password is. Get a detailed analysis with entropy score and improvement tips.
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Example Strong Passwords
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Tr0ub4dor&3!xKVery Strongcorrect-horse-battery-stapleVery StrongP@ssw0rd!2024#SecureVery StrongX7$mK9pL2@vQ4wR8Very StrongAdvertisement
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. (Source: Wikipedia — Password strength)
The National Institute of Standards and Technology (NIST) publishes guidelines for digital identity authentication in Special Publication 800-63B. NIST recommends longer passphrases over complex short passwords, discouraging arbitrary composition rules in favor of checking against known breached passwords. (Source: NIST SP 800-63B)
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