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Password Strength Checker

Check password strength, entropy and estimated crack time with a 5-level meter and improvement tips. Everything runs in your browser and is never sent to any server.

Last updated: 2026/10/16 Developer Feedback & bug reports

Your password is never sent off your device. All analysis happens entirely inside your own browser.

Enter a password to begin
0bits Entropy
— Est. crack time
0 Length
0 Character pool

* Rough estimate assuming an offline attacker trying 10 billion fast-hash guesses per second.

Checklist

  • 12+ characters
  • Lowercase (a-z)
  • Uppercase (A-Z)
  • Digits (0-9)
  • Symbols (!@#$...)

Improvement Tips

    How to Use

    1

    Enter a Password

    Type the password you want to check. Analysis starts as you type, and nothing is sent to any server.

    2

    Review Strength & Risks

    See the 5-level meter, entropy (bits), estimated crack time, and any detected weak patterns.

    3

    Improve with Tips

    Use the tips and checklist to add length and character variety for a safer password.

    About the Password Strength Checker

    A web tool that instantly evaluates how safe your password is. It rates strength on a 5-level scale from length, character variety and estimated entropy (bits), and shows the estimated brute-force crack time plus risky patterns such as common passwords, sequences and repeats. All processing happens in your browser, so your password is never transmitted anywhere.

    Features

    • Real-time AnalysisStrength, entropy and crack time are recalculated instantly as you type.
    • Fully In-BrowserYour password is analyzed locally and never sent to any server.
    • Entropy & Crack TimeShows estimated entropy (bits) and brute-force crack time in plain language.
    • Weak Pattern DetectionDetects common passwords, sequences, keyboard runs and repeated characters.

    Use Cases

    • Verify a new password before you start using it
    • Understand the risk of a reused password
    • Reference for company or team password policies
    • Review passwords for critical accounts (bank, email)
    • Check the strength of passwords from a generator

    FAQ

    Is my password sent anywhere?
    No. All analysis runs entirely in your browser with JavaScript. Your password is never sent to or stored on any server or external service.
    What is entropy (bits)?
    It measures how hard a password is to guess — higher is safer. It is derived from the size of the character pool and the length. Roughly, 60+ bits is strong and 80+ bits is very strong.
    How is the crack time estimated?
    It assumes an offline attacker making 10 billion fast-hash guesses per second. Real-world crack time varies greatly with the attack method and hashing scheme, so treat it as a rough guide.
    What makes a password safe?
    Mix uppercase, lowercase, digits and symbols, and use at least 12 characters (16+ is better). Avoid real words, birthdays and keyboard runs, and use a unique password for every service.
    Can I use it on my smartphone?
    Yes. It works on all modern browsers across smartphones, tablets and PCs. No registration or installation required.

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