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Password Strength Checker

Check your password strength with entropy calculation, crack time estimates, and actionable tips. Fully local analysis — your password never leaves your browser.

FreeNo SignupNo Server UploadsZero Tracking
This password is checked locally -- it never leaves your browser.

How to Use Password Strength Checker

  1. 1

    Enter your password

    Type or paste a password into the input field. The text is visible so you can verify what you're checking.

  2. 2

    Review the analysis

    See the strength meter, entropy bits, estimated crack time, and security checks.

  3. 3

    Follow improvement tips

    If your password is weak, follow the provided tips to make it stronger.

Frequently Asked Questions

Yes. Your password is analyzed entirely in your browser using JavaScript. It is never sent to any server. You can verify this by disconnecting from the internet and using the tool offline.

Entropy is calculated based on the character set size and password length: entropy = length x log2(charset_size). Penalties are applied for common patterns, dictionary words, and keyboard walks.

Crack time estimates how long a brute-force attack would take assuming 10 billion guesses per second (a modern GPU cluster). Real-world times may vary based on the attacker's resources and the hashing algorithm used.

The input is intentionally a text field (not a password field) so you can see exactly what you're checking. Since the check is fully local, there's no risk of the password being intercepted.