Password Strength Checker
Check how strong your password is. Analyze entropy, estimated crack time, and get improvement suggestions.
About This Tool
Check how strong your password is. Analyze entropy, estimated crack time, and get improvement suggestions. All operations are performed entirely in your browser for maximum security. No data is ever sent to any server.
crypto.getRandomValues(), a cryptographically secure random number generator built into your browser.
How to Read the Result
A password strength result is most useful when you treat it as a comparison tool, not a final guarantee. Look at length, character variety, repetition, and predictability together. A shorter password with mixed symbols can still be weaker than a long, unique passphrase if the structure is easy to guess.
What to Improve First
If your score is weak, the fastest improvement is usually adding length and removing familiar patterns such as names, years, keyboard sequences, or predictable substitutions. The goal is not just complexity on paper, but resistance to both automated guessing and human pattern recognition.
Frequently Asked Questions
Is my password sent to a server?
No. All analysis happens entirely in your browser. Your password never leaves your device.
What is entropy?
Entropy measures the randomness of a password in bits. Higher entropy means a more secure password. 80+ bits is considered very strong.