Password Strength Checker

Analyze the strength of your existing passwords with our advanced, client-side tool

Your password is analyzed locally in your browser and never sent to our servers.

How Our Password Strength Checker Works

Our tool performs a multi-faceted analysis of your password, all within your browser, to provide a comprehensive security score. Here's a breakdown of our methodology:

  1. Entropy Calculation: We calculate the password's entropy, which is a measure of its unpredictability. The formula we use is E = L * log2(N), where E is entropy in bits, L is the password length, and N is the size of the character set (e.g., 26 for lowercase letters, 95 for a mix of all character types).
  2. Pattern Matching: We check for common patterns, such as repeated characters (e.g., "aaaa"), sequences (e.g., "1234"), and keyboard patterns (e.g., "qwerty").
  3. Dictionary Checks: We compare your password against a list of common words, names, and known weak passwords.
  4. Crack Time Estimation: Based on the entropy and our pattern analysis, we estimate how long it would take a standard desktop computer to crack your password using a brute-force attack.
  5. Have I Been Pwned Integration: We securely check your password against the Have I Been Pwned database of breached passwords using the k-anonymity model, which ensures your full password is never exposed.

Interpreting Your Results

Understanding your password strength score is the first step to improving your security. Here's what the different strength levels mean:

  • Very Weak: Your password can be cracked almost instantly. It is likely a common word, a short sequence of characters, or has been seen in a data breach.
  • Weak: Your password provides minimal protection and can be cracked in a matter of minutes or hours.
  • Fair: Your password offers a moderate level of security but could be improved. It might be long enough but lacks complexity, or vice-versa.
  • Strong: Your password provides a good level of security and would take a significant amount of time to crack.
  • Very Strong: Your password is highly resistant to brute-force attacks and provides excellent security.