Password Strength Checker
Analyze locally as you type, with common patterns and practical suggestions.
Analysis starts after a short pause in typing. Input is not saved.
Up to 256 UTF-16 units; some emoji use 2 units. Longer input is rejected, never truncated.
Requires a modern browser with Workers and a secure connection.
Strength analysis
Enter a password to see its estimated strength, common patterns and suggestions.
Processed content stays in this page’s memory and cannot be recovered after clearing or closing.
About this tool
Uses zxcvbn with common, English and Chinese dictionaries in a browser Worker. Passwords, scores, lengths and matched fragments are never sent to the server or third parties. Scores are estimates, not security guarantees or breach checks.
How to use
- Type or paste a password; analysis starts after a short pause.
- Review the estimated level, patterns and suggestions. Show or hide without clearing input.
- Adjust your password, then clear or close the page.
Frequently asked questions
Is the password saved or uploaded?
No. Passwords are processed only in page and local Worker memory. Each started analysis counts as one use. The server records only run status, duration and count, never passwords, scores, lengths or patterns.
Does the highest score guarantee security?
No. The score is a model estimate and does not check actual breaches or account context. Use unique passwords and multi-factor authentication.
Why is there an input limit?
Analysis is limited to 256 UTF-16 units to bound browser work; the administrator may lower it. Some emoji use two units. Longer input is rejected rather than silently truncated.
Discussion & comments
Share your experience and discover more ways to use this tool.
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