About this tool
Evaluate password strength with a practical score, entropy upper estimate, character-class coverage, and checks for common passwords, predictable sequences, and repeated characters. Use the result to improve password policy guidance or review a candidate before storing it in a password manager. The score cannot detect every leaked or dictionary password and does not replace breach monitoring, MFA, rate limiting, or secure backend hashing. Analysis runs locally in your browser, so the password is not uploaded.
Practical Notes
Strength checks should guide users, not just block them. Clear feedback improves security and conversion at the same time.
UX and policy
Show specific reasons for weakness, such as short length or repeated patterns.
Align checker rules with backend policy to prevent pass-in-UI but fail-on-submit frustration.
Security posture
Encourage passphrases and prohibit common leaked password patterns.
Combine strength checks with rate limiting and MFA for meaningful risk reduction.
Use It In Practice
Password Strength Checker is most reliable with real inputs and scenario-driven decisions, especially around "Service accounts managed by vault/secret manager".
Use Cases
- When Service accounts managed by vault/secret manager, prioritize Use high-entropy random strings with strict rotation..
- When Human-entered credentials with frequent login, prioritize Use long passphrases plus MFA and risk-based controls..
- Compare Complexity vs Length for Password complexity vs password length before implementation.
Quick Steps
- Paste the password candidate.
- Review the strength level and entropy estimate.
- Use the result to improve length or variety before adoption.
Avoid Common Mistakes
- Common failure: Strength score appears acceptable while account takeover risk stays high.
- Common failure: Looks complex but remains highly guessable in targeted attacks.