Password Strength & Entropy Analyzer
Analyze password security and Shannon entropy bits with offline GPU crack time estimations, common pattern detection, and a cryptographically secure password generator.
🛡️ Password Strength & Entropy Analyzer
Analyze password security and Shannon entropy bits with offline GPU crack time estimations, common pattern detection, and a cryptographically secure password generator.
⏱️ Estimated Time to Crack (Brute-Force)
📋 Security Checklist & Recommendations
🎲 Secure Password Generator
📖 Understanding Password Entropy and NIST Guidelines
What is Password Entropy?
Entropy measures the unpredictability of a password in bits. Each additional bit doubles the number of guesses an attacker must make. Passwords with 60+ bits resist common brute-force attacks, while 80+ bits resist nation-state supercomputers.
Length Trumps Complexity
According to NIST SP 800-63B guidelines, a long passphrase of 4 random words (e.g. `correct-horse-battery-staple`) is far more secure and memorable than a short complex string like `P@$$w0rd`.
The Danger of Common Dictionary Words
Attackers don't guess every letter from A to Z — they use leaked database wordlists and rule-based permutation engines (like Hashcat). Avoid names, birthdays, and keyboard sequences.
❓ Frequently Asked Questions
Is it safe to type real passwords into this tool?
Yes. This tool is 100% client-side and performs all Shannon entropy calculations and checks inside your browser's local memory. You can even disconnect your internet and it will work identically.
How many bits of entropy are considered secure?
Under 40 bits is very weak and crackable in seconds. 40-60 bits is fair for low-risk accounts. 60-80 bits is strong. 80+ bits provides military-grade resilience against offline GPU clusters.
How are the brute-force crack times calculated?
Crack time is calculated by dividing total combinations (2^Entropy) by the attack speed. For offline cracking, we simulate modern hash cracking rates (100 billion guesses/sec on modern GPU rigs).
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