🛡️ Password Strength Checker

About this Password Strength Checker

This checker estimates a password's entropy — the real mathematical measure of how hard it is to guess — and tests it against the rules that matter: length, mixed case, digits and symbols. It also flags a handful of the world's most common passwords. The check runs 100% in your browser; the password is never sent anywhere, so it is safe to test real ones.

How to use it

1. Type or paste the password you want to evaluate.
2. Watch the entropy score and verdict update as you type.
3. Work through the checklist and fix anything marked with a cross.
4. Aim for 80+ bits: a long phrase with mixed characters beats a short clever one.

Example

'Tr0ub4dor' scores around 50 bits (Fair), while a four-word phrase like 'correct horse battery staple 42!' passes 100 bits and would take effectively forever to brute-force.

Frequently asked questions

Is it safe to type my real password here?

Yes. The analysis happens entirely in this page on your device — nothing is transmitted, stored or logged. Still, good practice is to test a similar password, not the exact one.

What matters more: length or symbols?

Length. Every extra character multiplies the guessing work, so a long memorable phrase usually beats a short password stuffed with symbols.

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