🔐 Password Tools

How It Works

This tool uses the Have I Been Pwned database to check if your password has appeared in any known data breaches. Your privacy is protected using k-anonymity:

• Your password is never sent over the internet
• Only the first 5 characters of the SHA-1 hash are sent to the API
• The API returns a list of all hashes matching that prefix
• The full comparison happens locally in your browser

If your password appears in the database, you should change it immediately to protect your accounts.

Understanding Password Entropy

Entropy measures the randomness or unpredictability of a password. It's calculated as:

Entropy = log₂(Character Set Size) × Password Length

Entropy Guidelines:

• 0-40 bits: Very Weak - Easily cracked
• 40-60 bits: Weak - Crackable with moderate effort
• 60-80 bits: Fair - Reasonable security for most purposes
• 80-100 bits: Good - Strong security
• 100+ bits: Strong - Excellent security (recommended for sensitive accounts)
• 128+ bits: Very Strong - Military-grade security

Note: Entropy is just one factor in password security. Also consider using unique passwords, enabling 2FA, and avoiding common patterns.