Password Strength Checker

Strength Enter password
8+ characters
Uppercase (A-Z)
Lowercase (a-z)
Number (0-9)
Special (!@#$)
12+ characters
0
Length
0
Entropy (bits)
0
Charset Size
0
Score / 100
Estimated Crack Time
Time to brute-force at 10 billion guesses/sec
Enter a password to analyze

100% Private

All analysis happens in your browser. No data is ever sent to any server. Your passwords stay completely private.

Password Tips

  • Use at least 12+ characters
  • Mix uppercase, lowercase, numbers & symbols
  • Avoid common words or patterns
  • Use a unique password for each account
  • Consider using a password manager

Strength Levels

Very Weak (0-20)
Weak (21-40)
Fair (41-60)
Strong (61-80)
Very Strong (81-100)

Entropy Calculation

Measures the mathematical unpredictability of your password based on character sets used.

Crack Time Estimate

Estimates how long it would take a supercomputer to brute-force guess your password.

Real-Time Analysis

Instant feedback as you type with visual strength indicators and detailed criteria checklist.

Why Password Entropy Matters

Length is often more important than complexity. A 20-character phrase is harder to crack than an 8-character complex string.

  • Brute Force Protection

    Every extra bit of entropy doubles the time required to guess the key.

  • Dictionary Attacks

    Using random words avoids common dictionary hacks used by attackers.

How to use

1

Type Password

Enter a password to test - analysis happens in real-time.

2

View Analysis

See strength score, entropy, and estimated crack time instantly.

3

Generate Strong Password

Use our generator to create a secure random password.

This tool runs 100% in your browser. No data is sent to any server.