Password Strength Checker

Check password strength free online. Get security feedback, improvement suggestions. Instant analysis, browser-based, no registration, security tool.

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Password Strength Checker

Test your password security and get instant feedback on how to improve it.

Enter a password to check its strength
o At least 8 characters
o Uppercase letter
o Lowercase letter
o Number
o Special character
o Not a common password

Password Strength Features

Comprehensive password security analysis.

Strength Meter

Visual strength meter from Very Weak to Very Strong.

Entropy Score

Shows password entropy bits for technical insight.

Pattern Detection

Detects common patterns, keyboard walks, and repeats.

How to Check Your Password Strength

  1. Type a password into the field

    Enter the password you want to test in the input box. The check runs the moment you type, so there is no submit button to press. Everything is analyzed by JavaScript in your browser, and the password stays on your device.

  2. Read the meter and requirement checks

    Watch the colored strength meter move from Very Weak to Very Strong and read the matching label. Below it, six checks light up: at least 8 characters, an uppercase letter, a lowercase letter, a number, a special character, and whether it matches a known common password.

  3. Review the crack time and improve

    The tool prints an estimated crack time based on the character set you used and the length. Use the Show button to reveal the text while editing, then add length and missing character types until the meter and crack time both improve.

What the Checker Measures

The score is built from a small set of concrete signals rather than a single rule. Each signal below either adds to the score or, in the case of a common password, subtracts from it. The result is mapped to one of five strength levels.

SignalHow it is testedEffect on score
Length 8+Password is at least 8 charactersAdds 1 point
Length 12+ and 16+Longer passwords pass extra length tiersAdds 1 point at each tier
Character varietyPresence of uppercase, lowercase, numbers, and symbolsAdds 1 point per type used
Common passwordMatched against a built-in list of weak passwordsSubtracts up to 3 points
Simple patternsRepeated characters or sequences like 123 or abcTreated as common and penalized
Crack timeCharset size raised to the length, at 1 billion guesses per secondShown as an estimate, not scored

Which Result Should You Aim For

Very Weak or Weak

Usually short passwords, a single character type, or a match against the common password list. The estimated crack time often reads as instant. Rewrite the password entirely before using it anywhere.

Fair

You have some variety and length but are missing a character type or are still on the short side. Acceptable for low-value logins only. Add length and a symbol to move up a level.

Strong

Twelve or more characters with a good mix of character types and no common pattern. Suitable for most accounts. Reach for 16 plus characters on anything that protects money or identity.

Very Strong

Long, mixes uppercase, lowercase, numbers, and symbols, and avoids known patterns. The crack time estimate climbs into years or beyond. Ideal for password managers, email, and primary accounts.

Common Problems and Fixes

The meter stays empty

The analysis runs only while the field has text. If the box is empty the meter, label, and crack time are cleared on purpose. Type at least one character and the checks will respond immediately.

A long password still scores low

Length alone is not enough if it matches the common list or is built from repeats or simple sequences such as aaaaaa or 123456. Those trigger the common penalty. Break the pattern by mixing unrelated characters and casing.

The crack time seems optimistic or harsh

The estimate assumes a fixed rate of one billion guesses per second and only counts the character classes you actually used. It is a rough guide for comparison, not a guarantee. Real attack speeds vary with the hashing method used by a site.

I cannot tell what I typed

The field is masked by default. Click the Show button to reveal the text while you edit, then click Hide to mask it again. The password stays on your device throughout and is not sent anywhere.

References

  1. Password strength - overview
  2. NIST SP 800-63B: Digital Identity (passwords) - NIST
  3. Entropy (information theory) - overview
  4. zxcvbn - realistic password strength estimation
  5. Password cracking - overview
  6. Password special characters - OWASP
  7. Dictionary attack - overview
  8. Pwned Passwords - Have I Been Pwned