Password Strength Checker
Analyze your password strength with real-time feedback and security recommendations.
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Estimated Crack Time
Detailed Analysis
Suggestions
Why Password Strength Matters
A strong password is your first line of defense against unauthorized access. Weak passwords can be cracked in seconds using modern hardware, while strong passwords can take millions of years to brute-force.
What Makes a Password Strong?
- Length - At least 12 characters is recommended; every extra character exponentially increases crack time
- Character variety - Mix uppercase, lowercase, numbers, and special characters
- No patterns - Avoid keyboard sequences (qwerty), dictionary words, and repeated characters
- Uniqueness - Never reuse passwords across different accounts
Understanding Entropy
Entropy is measured in bits and represents the randomness of a password. Higher entropy means more possible combinations and harder to crack:
- 40 bits - Weak (easily crackable)
- 60 bits - Moderate
- 80 bits - Strong
- 128+ bits - Very strong (effectively uncrackable)
Frequently Asked Questions
How is crack time calculated?
Crack time is estimated based on the password's entropy and assumed attack speeds. Offline attacks assume ~10 billion guesses/second (modern GPU cluster), while online attacks assume ~100 guesses/second (throttled by server).
Is my password sent anywhere?
No. All analysis happens entirely in your browser using JavaScript. Your password never leaves your device and is never stored or transmitted.
Should I use a password manager?
Yes. Password managers generate and store strong, unique passwords for every account. You only need to remember one master password. This is the recommended security practice.