Advanced Password Checker

Online Password Strength Checker: local structure analysis first, optional breach check second

This page helps you judge whether a password is easy to guess, built on common patterns, or worth replacing. A password such as P@ssw0rd!23 may look complex, yet still score poorly because it relies on a familiar word, predictable substitutions, or an obvious number sequence.

The current tool works in two separate layers:

• Local structure analysis: runs in your browser to estimate strength, entropy, crack time, password strategy, and concrete remediation steps.
• Optional breach exposure check: runs only when you click “Check Breach Exposure,” using HIBP's k-anonymity model to look for public breach matches without sending your raw password.

Those two signals answer different questions. A password can be structurally decent but still unsafe if it has already appeared in breach data. It can also be absent from known breach data while still being weak or too guessable for important accounts.

What this version of the tool actually does

• Evaluates dictionary words, dates, keyboard paths, repeated chunks, and other predictable patterns.
• Offers three guidance lenses: balanced everyday use, memorable passphrase-oriented use, and random password-manager use.
• Builds a local deep-analysis report with primary risk, recommended actions, and strategy-specific advice.
• Shows nuanced breach states such as not checked, checking, not found, compromised, and error.

If you only need a quick structural check, the local analysis is enough to get started. If the password will protect an important account, running the optional breach check adds a separate trust signal. The page does not store your password, and the default analysis flow does not need to send it to a server.