Password Strength Checker
Find out how strong your password really is. Real-time entropy analysis, crack time estimation, and actionable tips — all in your browser.
About This Tool
This tool analyzes your password locally in your browser. It calculates entropy based on character pool size and length, estimates offline crack time at 10 billion guesses per second, and provides specific tips to improve your password strength. No data is ever transmitted or stored.
Features
📊 Real-Time Analysis
Instant entropy and strength calculation as you type.
⏱️ Crack Time Estimate
See how long it would take to brute-force your password.
💡 Smart Tips
Actionable suggestions to make your password stronger.
🛡️ 100% Private
Everything runs locally. Your password never leaves your device.
Frequently Asked Questions
Is it safe to enter my password here?
Yes. This tool runs entirely in your browser. No data is sent to any server, stored, or logged.
How is entropy calculated?
Entropy = log2(pool_size) × length. The pool size depends on which character types your password uses (lowercase, uppercase, digits, symbols).
What crack time model is used?
We assume an offline brute-force attack at 10 billion guesses per second, which represents a strong GPU cluster attacking a password hash.
What makes a strong password?
Use 12+ characters with a mix of uppercase, lowercase, numbers, and symbols. Avoid dictionary words and personal info.