Check Password Security
Check how secure your password is with our free online tool. Get instant analysis of entropy, crack time, and character diversity.
Wondering how secure your password really is? Our password security checker provides a comprehensive analysis of your password strength using industry-standard metrics. The tool calculates Shannon entropy, estimates brute-force crack time assuming 10 billion guesses per second, and identifies which character categories you are using. All processing happens locally in your browser, so your password is never transmitted over the network. This makes it safe to check even your most sensitive passwords without any privacy concerns.
How to Use This Tool
- 1. Navigate to the password input field
- 2. Enter the password you want to check
- 3. Observe the animated strength bar fill up
- 4. Review entropy bits and crack time estimates
- 5. Check the character category indicators for completeness
Why Use This Tool
- Zero-knowledge architecture ensures total privacy
- Animated visual feedback for intuitive understanding
- Entropy measured in bits for technical accuracy
- Crack time based on realistic attack scenarios
- Free to use with no registration required
Frequently Asked Questions
What is Shannon entropy?
Shannon entropy measures the unpredictability of a password. Higher entropy means more randomness and greater resistance to guessing attacks.
Why does character variety matter?
Using multiple character types (lowercase, uppercase, digits, symbols) increases the pool size, which exponentially increases the number of possible combinations.
Is 10 billion guesses per second realistic?
Yes, modern GPU clusters can achieve this rate for simple hash functions. Properly salted and hashed passwords with bcrypt or Argon2 are much slower to crack.
Should I check all my passwords?
Yes, especially for critical accounts like email, banking, and cloud services. Use unique strong passwords for each account.