Password Strength Analyzer
SecurityAnalyze password strength and get recommendations for improvement. All analysis is done locally - your password never leaves your browser.
What is This Tool?
A password strength analyzer evaluates passwords for security by measuring entropy, detecting common patterns, checking against breach databases, and providing specific improvement suggestions. Get a detailed breakdown of what makes your password strong or weak.
Password strength depends on more than length — entropy (randomness), pattern avoidance (no keyboard walks, dates, or dictionary words), and uniqueness (not found in data breaches) all matter. This tool uses heuristic analysis similar to zxcxbn to provide realistic strength estimates.
Common Use Cases
Password Policy Design
Test different password compositions to calibrate your application's password strength requirements and user guidance.
Security Awareness
Educate users about what makes passwords strong by showing the impact of length, character variety, and pattern avoidance.
Compliance Verification
Verify that passwords meet NIST SP 800-63B guidelines and organizational security policy requirements.
Development Testing
Test your application's password strength meter against this reference implementation to ensure accurate user feedback.
Frequently Asked Questions
How is password strength measured?
Entropy (bits of randomness), pattern detection (sequences, repeats, keyboard walks), dictionary checks, and breach database matching provide a comprehensive score.
Is my password sent to a server?
No. All analysis happens in your browser. Your password never leaves your device.
What does NIST recommend?
NIST SP 800-63B recommends minimum 8 characters, checking against breach databases, no composition rules (uppercase/symbol requirements), and no periodic rotation.