How is password entropy calculated?

Entropy is calculated using the formula: E = L × log₂(R), where L is password length and R is the size of the character set (26 for lowercase, 52 for mixed case, etc.). We also reduce entropy for common patterns and dictionary words.

What is a good entropy score?

For most accounts, aim for 60+ bits (Good). Financial accounts should have 80+ bits (Strong). Master passwords and critical accounts need 100+ bits (Very Strong).

Are the crack time estimates accurate?

Our estimates are based on current attack capabilities and assume the attacker knows your password character composition. Real-world crack times vary based on attack methods, hashing algorithms, and whether the password is in rainbow tables.

Why check for personal information?

Passwords containing personal information (name, birthdate, username) are easier for attackers to guess through social engineering. Our tool detects these patterns and warns you, helping you create truly random passwords.

Is it safe to type my password here?

Yes, the analysis happens entirely in your browser. Your password is never sent over the internet.

Password Entropy & Time-to-crack Estimator

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Understanding Entropy

Entropy measures password randomness in bits. Higher entropy = harder to crack.

• <40 bits: Weak - crackable in hours/days

• 40-60 bits: Fair - crackable in weeks/months

• 60-80 bits: Good - crackable in years

• 80-120 bits: Strong - crackable in centuries

• 120+ bits: Very Strong - practically uncrackable

What is Password Entropy?

Password entropy is a measurement of how unpredictable and random a password is. It's expressed in bits, where each additional bit doubles the number of possible combinations. Higher entropy means a password is more resistant to guessing and brute-force attacks.

Measured in Bits: Each bit doubles possible combinations
Randomness Factor: More random = higher entropy = stronger
Attack Resistance: Predicts time needed to crack password
Security Metric: Industry-standard password strength measurement
Private: Passwords are analyzed locally and never uploaded

How to Use

Enter or paste the password you want to analyze
View real-time entropy calculation and strength rating
Check estimated crack time under different attack scenarios
Review suggestions for improving password security
Verify the password meets your security requirements

Entropy & Security Glossary

Entropy: A measure of randomness or unpredictability in a password, expressed in bits.
Bits of Entropy: Each bit represents a doubling of password complexity. 80+ bits is considered strong.
Brute Force: Systematically trying all possible password combinations until finding the correct one.
Attack Vector: A method or pathway used by attackers to gain unauthorized access to a system.
Character Space: The total number of possible characters available for password creation.
Guesses Per Second: The rate at which an attacker can attempt password combinations.
Common Password: Frequently used passwords that appear in breach databases and are easily guessed.
Password Policy: Rules defining minimum requirements for acceptable passwords in a system.

Frequently Asked Questions about Password Entropy & Time-to-crack Estimator

Entropy is a measure of the unpredictability or randomness of a password. Higher entropy means the password is harder to guess or crack.

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