Password Strength Checker

Type a password above to see its strength analysis.

How is Password Strength Calculated?

This tool uses the zxcvbn library — the same algorithm used by major sites like Dropbox. Instead of simple rules ("must have 1 uppercase"), zxcvbn analyzes patterns like dictionary words, keyboard sequences, dates, and common substitutions to estimate how many guesses an attacker would need. The crack time is estimated against an offline slow-hash attack at 10,000 guesses/second.

How to Use the Password Strength Checker

Type or paste a password into the field above.
The strength score (0–4), crack time, and entropy are shown instantly.
Read the warning and suggestions to understand weaknesses.
Nothing is sent to any server — all analysis runs in your browser.

Entropy measures the unpredictability of your password in bits — the higher, the better. A charset size of 94 means you're using all printable ASCII characters.

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