Password strength depends on length, complexity, and unpredictability. A 12-character random password with mixed case, numbers, and symbols has ~78 bits of entropy — enough to resist brute-force attacks for billions of years. This checker analyzes all these factors without ever transmitting your password.
How to Use
Type your password to see:
- Strength score: Weak/Fair/Good/Strong/Very Strong
- Entropy: Bits of randomness
- Crack time: Estimated time to brute-force
- Issues: Detected weaknesses
What is Entropy?
Password entropy = log₂(pool_size^length). A character pool of 95 (all printable ASCII) with 12 characters = log₂(95¹²) ≈ 78.8 bits. Each additional bit doubles the search space.
Strong Password Tips
- Use 14+ characters (length matters most)
- Mix uppercase, lowercase, numbers, symbols
- Avoid dictionary words and personal info
- Use a password manager for unique passwords
- Consider passphrases: 'correct horse battery staple'
Step-by-Step Instructions
- 1Type your password in the input field.
- 2View the strength score and entropy.
- 3Check the estimated crack time.
- 4Review detected weaknesses.
- 5Follow improvement suggestions.