Password Strength Checker — How Strong Is My Password?
Check how strong your password is with real-time entropy analysis, crack-time estimates, and pattern detection. Get suggestions to improve weak passwords. Free and private.
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Frequently asked questions about strength checker.
How does the strength checker work?
It uses zxcvbn, an advanced algorithm developed by Dropbox. It detects common patterns like dictionary words, keyboard sequences, dates, repeated characters, and l33t substitutions to estimate how long a password would take to crack.
Is my password sent to any server?
No. The entire analysis runs in your browser. Your password never leaves your device. You can verify this by checking the network tab in your browser's developer tools.
What is entropy?
Entropy measures the randomness of a password in bits. Higher entropy means more possible combinations an attacker must try. A password with 60+ bits of entropy is generally considered strong.
What does the crack time estimate mean?
It estimates how long it would take to crack your password using offline brute-force attacks at 10,000 guesses per second. Real-world attack speeds vary, but this gives a useful baseline comparison.