Password Strength Checker
Test any password for strength. Everything runs client-side — your password is never sent anywhere.
Your password is checked entirely in your browser. It is not stored or transmitted anywhere.
About This Password Strength Checker
This free password strength checker analyzes your password in real time and provides detailed feedback on its security. It evaluates character diversity, length, common patterns, and estimates how long it would take an attacker to crack your password using brute-force methods. All analysis happens entirely in your browser — your password is never sent to any server.
How to Use
- Type or paste a password into the input field above.
- View the strength meter, which rates your password from Very Weak to Very Strong.
- Check the criteria list to see which requirements your password meets.
- Review the estimated crack time to understand your password's resistance to brute-force attacks.
- Follow the improvement suggestions to make your password stronger.
Frequently Asked Questions
Is my password safe when using this tool?
Yes. Your password never leaves your browser. All strength analysis is performed using client-side JavaScript with no network requests. You can verify this by disconnecting from the internet and using the tool offline.
How is the crack time estimated?
The crack time estimate assumes an attacker performing 10 billion guesses per second (a realistic rate for modern GPU-based cracking). It calculates the total number of possible combinations based on the character sets used and the password length.
What makes a password "Very Strong"?
A Very Strong password meets at least 5 of the 6 criteria: 8+ characters, uppercase letters, lowercase letters, numbers, special symbols, and no common patterns. Passwords 16+ characters long with diverse character sets achieve the highest rating.
Should I use a passphrase instead?
Passphrases (random words strung together like "correct horse battery staple") can be both strong and memorable. A 4-5 word passphrase with some numbers or symbols added is an excellent approach to password security.