Password Strength Checker
Check password strength with entropy calculation and crack time estimates. 100% private.
Your password never leaves your browser. All strength analysis is performed entirely on your device. Nothing is sent to any server.
How to Use This Password Strength Checker
Check the strength of your passwords in real time. Get instant feedback on security, entropy, and estimated crack time.
- Type or paste a password into the input field
- View the strength meter and score instantly
- Check the entropy and estimated crack time
- Follow the suggestions to improve weak passwords
Tip: A strong password should be at least 12 characters long and include a mix of uppercase, lowercase, numbers, and special characters. Passphrases (like "correct-horse-battery-staple") are both strong and memorable.
FAQ
Is it safe to type my real password here?
Yes. Your password is analyzed entirely in your browser using JavaScript. It is never sent to our servers or any third party. You can verify this by checking your browser's network tab.
What is password entropy?
Entropy measures the randomness of a password in bits. Higher entropy means more possible combinations, making the password harder to crack. A password with 80+ bits of entropy is considered very strong.
How is crack time estimated?
We assume an attacker using a modern GPU cluster capable of 10 billion guesses per second. The estimate shows the average time to crack the password through brute force.