Password Strength Checker
Analyze password strength and get security recommendations for better passwords
Password Strength Checker
Analyze password strength and get security recommendations for better passwords
Quick Generator
Enter a Password
Start typing to see real-time strength analysis, entropy calculation, and security metrics.
About Password Strength and Security
Password strength measures how resistant a password is to brute force attacks and dictionary attacks. Strong passwords combine length, complexity, unpredictability, and uniqueness to protect against unauthorized access.
- Length: Longer passwords are exponentially harder to crack
- Complexity: Mix of uppercase, lowercase, numbers, and symbols
- Unpredictability: Avoid common words, patterns, and personal information
- Uniqueness: Different passwords for different accounts
- Entropy: Measure of randomness and information content
Password Strength Criteria
Strong Password Features
- 12+ Characters: Minimum length for good security
- Mixed Case: Both uppercase and lowercase letters
- Numbers: Include digits (0-9)
- Symbols: Special characters (!@#$%^&*)
- No Dictionary Words: Avoid common words
- No Personal Info: No names, dates, or addresses
Weak Password Patterns
- Short Length: Under 8 characters
- Common Passwords: "password", "123456", etc.
- Keyboard Patterns: "qwerty", "asdf", etc.
- Sequential: "abc123", "111111", etc.
- Substitution: "@" for "a", "3" for "e"
- Personal Data: Names, birthdays, addresses
Frequently Asked Questions
How to check password strength?
Type your password into the utilAZ strength checker. It analyzes length, character diversity, common patterns, dictionary words, and keyboard sequences to assign a score from Very Weak to Very Strong. Everything runs client-side so your password never leaves your device.
What makes a password strong?
A strong password is at least 12 characters long, uses a mix of uppercase, lowercase, digits, and symbols, avoids dictionary words and personal info, and is unique per account. Passphrases of 4-6 random words are equally strong and easier to remember.
How is password strength calculated?
Strength is calculated by measuring entropy (bits of randomness), checking against common password lists, detecting patterns like sequences and repeated characters, and estimating brute-force crack time based on character pool size and length.
What is password entropy?
Password entropy measures randomness in bits. It equals log2(pool_size^length). A 10-character password using 95 printable ASCII characters has about 65 bits of entropy. Higher entropy means more guesses needed to crack. 80+ bits is considered strong for most uses.
How long will it take to crack my password?
Crack time depends on password entropy and attacker speed. At 10 billion guesses per second, an 8-character lowercase password falls in under a second, while a 16-character mixed password takes billions of years. Our tool shows estimated crack time for multiple attack speeds.
Is my password in a data breach?
You can check via services like Have I Been Pwned which hold billions of leaked credentials. utilAZ checks your password against a local list of the most common compromised passwords without sending it over the network, keeping your password private.
Password Strength Examples
Weak Passwords:
Strong Passwords:
How Password Strength Analysis Works
Password strength is measured by estimating how long it would take an attacker to crack it using brute force or dictionary attacks. The analysis evaluates several key factors: length, character variety, entropy (randomness), and the presence of common patterns such as keyboard sequences or dictionary words.
Entropy Calculation
Entropy, measured in bits, quantifies how unpredictable a password is. It is calculated as
log₂(charsetSize) × length. A larger character set and longer password both increase entropy exponentially.
// Calculate password entropy in bits
function getEntropy(password) {
let pool = 0;
if (/[a-z]/.test(password)) pool += 26;
if (/[A-Z]/.test(password)) pool += 26;
if (/[0-9]/.test(password)) pool += 10;
if (/[^a-zA-Z0-9]/.test(password)) pool += 32;
return password.length * Math.log2(pool || 1);
}
// Example: "T3st!ng" → ~39 bits | "c0rr3ct-H0rse-Batt3ry!" → ~131 bitsThe tool above applies these calculations automatically, then flags common weaknesses including keyboard walks like "qwerty", sequential runs like "1234", repeated characters, and known breached passwords, giving you an actionable strength score with specific improvement suggestions.
Password Manager Best Practices
- Use a Reputable Manager: Choose established tools like 1Password, LastPass, Bitwarden
- Master Password: Create a very strong, unique master password
- Two-Factor Authentication: Enable 2FA on your password manager account
- Regular Backups: Export and securely store password database backups
- Security Audits: Use built-in tools to identify weak or reused passwords
- Browser Integration: Use official browser extensions for auto-fill
- Mobile Apps: Install official mobile apps with biometric unlock
Common Use Cases
- Personal account security assessment
- Corporate password policy compliance
- Security audit and penetration testing
- Password generation and validation
- User education and awareness training
- Identity and access management systems
- Compliance reporting and documentation
- Multi-factor authentication setup