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Password Strength Checker

Evaluate password strength with score, entropy estimate, and improvement tips.

Formula reviewed: 2026-02-14 Developer Tools

Password Strength Checker evaluates a password and returns a score, entropy estimate, and improvement guidance. It helps you identify weak patterns such as short length, missing character variety, and predictable composition. Use this before enforcing policy changes or when coaching users toward stronger credentials. The tool is intended for local evaluation and iteration so you can quickly improve a candidate password before deployment.

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Input Pattern

Enter values in the left panel, keep units explicit, run the calculation, then copy or share the result. Invalid fields are highlighted immediately.

How to use this tool

  1. Enter the candidate password exactly as it will be used.
  2. Run the checker and review score, entropy estimate, and warnings.
  3. Adjust length/complexity and rerun until the target strength threshold is reached.

Password Strength Input

Result

Score: 0/100

Rating: Very Weak

Estimated entropy: 0.00 bits

Length: 0

Character classes: lower=no, upper=no, digits=no, symbols=no

Suggestions:

  • Use at least 14 characters.
  • Add uppercase letters.
  • Add lowercase letters.
  • Add numbers.
  • Add symbols.

How to interpret the result

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