Evaluate password entropy and strength

For users and technical teams comparing password choices or explaining why one construction is stronger than another.

Gauge a password’s search space, entropy in bits and strength level to understand its estimated resistance before choosing it.

How to use

Enter the password you want to evaluate into the field provided for local analysis.
Run the evaluation to obtain the estimated search space and entropy in bits.
Compare the strength level shown with the requirements of the service you want to protect.
Try a longer or more varied version if the result seems insufficient.
Erase the field to compare another password without keeping the previous one visible.

Example

With the sample input Correct-Horse-2024, the tool estimates the search space and entropy. Look at how length and character variety change the bit value, then edit the password to observe the effect of each adjustment, such as adding a symbol or a word.

Input

Correct-Horse-2024

Limits and formats

Estimated entropy does not guarantee that a password will resist every attack.
A password built on a known pattern can have misleading theoretical entropy.
The tool does not check published breaches or the specific rules of each website.
The displayed bits are an estimate that depends on the calculation model used.
Use the estimate to compare options, not as a definitive security certification.

Where processing happens

The evaluation runs inside your browser. The password you type stays on your device and is not sent to any remote service. No data is kept after the analysis.

Frequently asked questions

What is entropy in bits?

It is a measure of how many possible combinations a password represents. A higher bit value means a larger search space, which makes an exhaustive guessing attempt harder.

Why do two passwords of the same length have different entropy?

Entropy also depends on character variety and patterns. A password made of common lowercase letters offers fewer combinations than one mixing uppercase letters, digits and symbols.

Can I rely only on the bit value shown?

No, it is a useful but partial estimate. You should also avoid common words, dates and predictable sequences, and use a unique password for each important service.