Password Strength Checker
Analyze your password strength with entropy, crack time estimates, and actionable suggestions.
The Password Strength Checker analyses a password with an entropy estimate, a crack-time estimate, and concrete suggestions for improvement. It gives you a clear sense of how strong a password really is.
What is a Password Strength Checker?
A password strength checker is a security tool that evaluates how resistant your password is to being cracked through brute force or dictionary attacks. It analyzes your password based on several factors including length, character variety (lowercase letters, uppercase letters, numbers, and special symbols), and entropy—the measure of unpredictability. This tool provides a comprehensive assessment that goes beyond simple complexity rules to give you a realistic evaluation of your password's security. A strong password is your first line of defense against unauthorized access to your personal and professional accounts in an increasingly digital world.
Understanding password strength is crucial because weak passwords are the easiest target for attackers. Many people reuse passwords across multiple sites or use easily guessable information like birthdays or common words. A strength checker helps you identify weaknesses and provides concrete suggestions for improvement. This is especially important for sensitive accounts like email, banking, and social media where a compromised password could lead to significant personal and financial damage. Password reuse across multiple sites means one breach could compromise many accounts and expose your digital identity and personal information to malicious actors.
This particular password strength checker runs entirely in your browser with no external dependencies or data collection. When you type your password, the tool immediately analyzes it and displays the results without ever sending your input to any server. The analysis includes entropy estimation, crack time calculations for various attack rates, a 0-4 strength score with a color-coded visual bar, and specific recommendations for strengthening your password. Your password exists only temporarily in memory as you type and is cleared when you leave the page or clear the field, ensuring complete privacy and protecting your sensitive information from potential exposure.
How to use this Password Strength Checker
- Enter your password in the input field above. The tool analyzes it as you type.
- Review the entropy estimate which measures unpredictability in bits.
- Check the estimated crack time at different attack rates (100/hour, 10K/sec, 1B/sec).
- Look at the 0-4 strength score with color-coded visual bar (gray to green).
- Read the suggestions section for concrete ways to improve your password strength.
FAQ
How is password strength calculated?
We calculate entropy based on character class usage (lowercase, uppercase, digits, symbols) and password length. Higher entropy means stronger resistance to brute force attacks.
What is entropy and why does it matter?
Entropy measures password unpredictability in bits. A password with 100 bits of entropy would require 2^100 guesses on average to crack. More entropy means exponentially harder cracking.
Does the password strength checker store my password?
No. All analysis happens entirely in your browser using client-side JavaScript. Your password is never uploaded, stored, or transmitted anywhere. It exists only temporarily in memory while you type.
What is a good password strength score?
Aim for score 4 (strong) with at least 80 bits of entropy. For highly sensitive accounts like email or banking, consider passwords with 100+ bits of entropy for maximum security.