Developer Tools

Password Strength Checker

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

Last validated: 2026-02-14

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.

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 use this tool

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

Worked Example

Auto-generated from the tool's current default or entered inputs.

Example Inputs

Password:
Length: 0
Has lower:
Has upper:
Has digit:
Has symbol:
Score: 0
Rating: Very Weak

Expected Outputs

Length: 0
Score: 0
Entropy bits: 0

Interpretation

Length is 0. Use this as a decision input, not as a standalone conclusion.
Score is 0. Use this as a decision input, not as a standalone conclusion.
Entropy bits is 0.0. Use this as a decision input, not as a standalone conclusion.
Cross-check the result against one alternate input set to validate sensitivity.

Scenario Compare (A vs B)

Use this to compare two input sets and quantify change in key outputs.

Scenario A

Password

Length

Has lower

Has upper

Has digit

Has symbol

Score

Rating

Scenario B

Password

Length

Has lower

Has upper

Has digit

Has symbol

Score

Rating

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Password Strength Checker

Input Pattern

Password Strength Input

Result

How to use this tool

Worked Example

Example Inputs

Expected Outputs

Interpretation

Scenario Compare (A vs B)

Scenario A

Scenario B

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