Password Strength Estimator
Estimate entropy and see what is weakening a password.
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About this tool
Estimates entropy from the length and character set of a candidate password. It measures the shape of the string, not whether it is guessable — a memorable phrase can score well and still appear in a breach corpus.
Limitations
- This is an entropy estimate based on character composition and obvious patterns. It is informational, not a security guarantee.
- Nothing typed here is stored or transmitted, but the safest habit is to test a password of the same shape rather than your real one.
Questions
- It scores my password highly but it feels weak.
- Trust that instinct. Entropy assumes the value is genuinely random; a predictable pattern that happens to use several character classes scores far better than it deserves.
Privacy
This page does its work in your browser. What you paste is processed by JavaScript running on your own device and is never sent to a DevToolery server — there is no server that could receive it. The page itself is a static file delivered by a CDN. See exactly what is stored.