🔐 Password Entropy Checker

Check your password's strength with detailed entropy analysis. Estimates crack time and identifies weaknesses. All computation happens locally in your browser.

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FAQ

What is password entropy?

Password entropy measures unpredictability in bits. Higher entropy means a more secure password. Generally, 80+ bits is considered secure.

How is password entropy calculated?

Formula: E = log₂(S^L) where S is character set size and L is length. Actual entropy also accounts for dictionary words and common patterns.

What makes a strong password?

A strong password: 12+ characters, mix of uppercase, lowercase, digits, and special chars, no common words or personal info, unique per site.

How long to crack a strong password?

A 12-char password with mixed case+digits+symbols (~80 bit entropy) would take billions of years with modern GPU brute force.