Password Strength Checker
Instant entropy analysis and actionable improvement tips
Everything runs in your browser. Your data never leaves your device.
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How to use
Understanding why a password is weak is the first step toward fixing it. This tool breaks down every dimension of password strength so you know exactly what to improve.
Type or paste your password
Enter the password in the input field. The strength score, entropy value, and suggestions update in real time as you type, so you can see the impact of each character you add.
Review the entropy and score
Entropy in bits tells you how much randomness the password contains. A score of 0–1 means it is easy to guess; aim for a score of 3 or 4 and at least 60 bits of entropy for sensitive accounts.
Follow the improvement suggestions
The suggestions panel lists specific changes — adding symbols, increasing length, avoiding repeated characters — so you can act on them immediately rather than guessing what to fix.
Examples
Common word with substitutions
A password like 'P@ssw0rd' scores Very Weak despite its mixed characters because it matches a well-known substitution pattern that is included in every serious cracking dictionary. The checker flags this immediately.
Random passphrase check
A four-word passphrase such as 'correct-horse-battery-staple' scores Very Strong because its length provides high entropy even though it uses only lowercase letters and hyphens, demonstrating that length matters more than complexity alone.
About this tool
Analyse any password to see its strength score (0 Very Weak to 4 Very Strong), estimated entropy in bits, and a list of concrete suggestions for making it better. The checker evaluates length, character variety, common patterns, and dictionary proximity. A show/hide toggle lets you verify what you typed without exposing it to shoulder-surfers. Your password never leaves your browser — no data is uploaded or logged.