FREE Password Strength Checker
🔒 100% Client-Side - Never Sent to Server
Password Strength Checker
Analyze your password security with entropy calculation
🔐
Your password never leaves your browser. All analysis is done locally in JavaScript. We don't store, transmit, or log any passwords.
Enter a password
0
Length
0
Unique Chars
0
Charset Size
0
Score /100
⚠️ Security Warnings
📋 Password Requirements
🔢 Entropy Analysis
0
bits of entropy
What is entropy? Entropy measures password randomness in bits. Each bit doubles the possible combinations.
• < 28 bits: Very weak - crackable in seconds
• 28-35 bits: Weak - crackable in minutes to hours
• 36-59 bits: Reasonable - crackable in days to months
• 60-127 bits: Strong - crackable in years
• 128+ bits: Very strong - practically uncrackable
• < 28 bits: Very weak - crackable in seconds
• 28-35 bits: Weak - crackable in minutes to hours
• 36-59 bits: Reasonable - crackable in days to months
• 60-127 bits: Strong - crackable in years
• 128+ bits: Very strong - practically uncrackable
Pro Tips for Strong Passwords
- Use a passphrase: "correct-horse-battery-staple" is stronger than "Tr0ub4dor&3"
- Aim for 16+ characters - length beats complexity
- Use a password manager to generate and store unique passwords
- Never reuse passwords across different accounts
- Enable two-factor authentication (2FA) whenever possible
- Avoid personal info like birthdays, names, or pet names