Password Strength Checker
Analyze password strength with zxcvbn. See score, crack time, and improvement tips instantly.
About this tool
Most people overestimate their password strength. This checker uses zxcvbn, the industry-standard open-source estimator developed at Dropbox, to analyze your password against real-world attack patterns. It gives you a score from 0 to 4, an estimated crack time, and actionable suggestions to improve — all without sending anything to a server.
How to use the Password Strength Checker
- Type or paste the password you want to analyze
- Watch the strength gauge update in real time as you type
- Check the estimated crack time and warning text
- Review the requirements checklist and follow suggestions to improve
Features
- Scientific strength score (0-4) using zxcvbn
- Estimated crack time against realistic attacks
- Warning text and actionable suggestions
- Visual checklist for length, uppercase, lowercase, numbers, and symbols
- Show/hide password toggle
- One-click password copy
- 100% client-side — no data sent
Frequently asked questions
Is this password strength checker free?
Yes. Analyze password strength instantly with no registration or cost.
Is my password sent to a server?
No. All analysis runs locally in your browser using the zxcvbn library. Your password never leaves your device.
What does the crack time mean?
It estimates how long it would take for an attacker with moderate resources (10,000 guesses per second) to guess your password using common patterns.
What is zxcvbn?
zxcvbn is an open-source password strength estimator developed at Dropbox. It measures real-world crackability better than naive character-count approaches.