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Password Strength Checker

Evaluate how strong a password really is.

What Is a Password Strength Checker?

The Password Strength Checker evaluates how resistant a password is to guessing and brute-force attacks. It scores the password from 0 to 4 based on length, character variety, and entropy, estimates how long it would take to crack at 10 billion guesses per second, and suggests concrete improvements. This free online security tool is useful for password strength checker, password security checker, password entropy checker. Common use cases include evaluating password length, character variety, entropy, and resistance to guessing. It is designed for quick browser-based analysis and development workflows. Security checks are signals rather than guarantees, so production systems should also be validated against current standards and their specific threat model.

How to Use This Password Strength Checker

  1. 1
    Enter the passwordType or paste the password you want to evaluate.
  2. 2
    Review the scoreCheck the strength level and entropy estimate.
  3. 3
    Check the lengthLonger passwords generally provide more resistance to guessing.
  4. 4
    Read the recommendationsFollow the suggested improvements where appropriate.
  5. 5
    Protect the passwordAvoid testing sensitive live credentials on services you do not trust.

Frequently Asked Questions

Entropy measures the unpredictability of a password in bits. Higher entropy means far more possible combinations and a longer time to crack. Length is the biggest factor.
A score of 4 means the password is very strong. Aim for at least 12 characters that mix uppercase, lowercase, digits, and symbols.
No. The password is analyzed entirely in your browser and never sent to or stored on a server.

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