Free Toolkit

Password Strength CheckerCheck how strong your password is with detailed scoring, crack time estimates, and improvement suggestions.

Password Strength Checker illustration
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Password Strength Checker

Check how strong your password is with detailed scoring, crack time estimates, and improvement suggestions.

How to Use
1

Enter Password

Type or paste the password to test.

2

Review Score

See strength rating 0-4 with visual meter.

3

Read Suggestions

Follow improvement suggestions.

What Is Password Strength Checker?

Analyzes passwords using the zxcvbn library (developed by Dropbox). Detects common passwords, dictionary words, keyboard patterns (qwerty), dates, repeated characters, and l33t speak substitutions. Provides realistic crack time estimates for different attack scenarios, a 0-4 score, and specific actionable suggestions. Runs entirely in your browser—your password is never transmitted.

Why Use Our Password Strength Checker?

  • Uses zxcvbn, the industry standard
  • Detects patterns and dictionary words
  • Realistic crack time estimates
  • Actionable suggestions
  • Completely client-side

Common Use Cases

Password Auditing

Test existing passwords to find weak accounts.

New Accounts

Verify password strength before using it.

Security Training

Demonstrate why certain patterns are weak.

Education

Learn what makes passwords strong or weak.

Technical Guide

zxcvbn uses pattern matchers: dictionary, spatial (keyboard), repeat, sequence, date, and l33t substitution. Score 0-4 maps to crack time thresholds based on minimum guesses required. Feedback includes warnings and suggestions.

Tips & Best Practices

  • 1
    Aim for score 3+
  • 2
    Long passphrases often beat short complex passwords
  • 3
    Avoid personal info
  • 4
    Use unique passwords per account

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Frequently Asked Questions

QIs my password sent to a server?
No. zxcvbn runs entirely in your browser.
QWhat does the score mean?
0=too guessable, 1=very guessable, 2=somewhat, 3=safely unguessable, 4=very unguessable.
QWhat is zxcvbn?
A realistic password strength estimator developed by Dropbox.

About Password Strength Checker

Password Strength Checker is a free online tool from FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration required. No ads. Just fast, reliable tools.