Password Strength Checker
Analyze your password strength with entropy calculation, pattern detection, and breach database checking. All analysis runs in your browser. Free password tool.
What Is Password Strength Checker?
A password strength checker analyzes your password against multiple criteria: length, character variety, entropy (randomness), common patterns, dictionary words, and known breach databases. It provides a strength rating and specific recommendations to improve your password security.
How to Use
Type your password into the checker. Analysis happens entirely in your browser; nothing is sent to any server. The tool instantly shows strength rating, estimated crack time, detected patterns, and improvement suggestions.
Use Cases
- Test existing passwords before reusing them
- Evaluate new passwords before setting them
- Learn what makes a password strong or weak
- Check if your password appears in breach databases
- Compare password strength across different approaches
Frequently Asked Questions
What makes a strong password?
A strong password is at least 16 characters long, uses a mix of uppercase, lowercase, numbers, and symbols, avoids dictionary words and common patterns, and is unique to each account. Passphrases (random word combinations) are both strong and memorable.
Is my password sent to a server?
No. All password analysis happens entirely in your browser using JavaScript. Your password never leaves your device. You can verify this by disconnecting from the internet and running the test offline.
How long would it take to crack my password?
Crack time depends on the attack method. A 8-character lowercase password: seconds. A 12-character mixed password: centuries. A 20-character passphrase: heat death of the universe. Length is the most important factor.