Password Strength Checker: Test Your Password Security
Our free password strength checker analyzes your passwords in real-time to determine their security level. Using advanced algorithms, we evaluate password entropy, character variety, common patterns, and vulnerability to various attack methods. All analysis happens locally in your browser - your passwords are never sent to our servers or stored anywhere.
How Password Strength is Measured
Password strength is measured using multiple factors including length, character diversity, entropy, and resistance to common attack patterns. Our checker evaluates passwords on a 100-point scale, considering uppercase and lowercase letters, numbers, special symbols, sequential patterns, repeated characters, and common password lists. A truly strong password scores 80+ points with high entropy.
What Makes a Password Weak?
- Short Length: Passwords under 12 characters are vulnerable to brute-force attacks
- Common Passwords: Using passwords like "password123" or "qwerty" that appear in breach databases
- Dictionary Words: Single words or common phrases are easily cracked by dictionary attacks
- Sequential Patterns: Sequences like "123456" or "abcdef" are predictable
- Repeated Characters: Patterns like "aaaaaa" or "111111" have low entropy
- Personal Information: Names, birthdays, or addresses are easily guessed
- Lack of Variety: Using only lowercase letters or only numbers reduces security
Understanding Crack Time Estimates
Online Attack (1000 guesses/sec): Represents attacks against live login systems with rate limiting. Most websites throttle login attempts to prevent brute-force attacks.
Offline Attack (1 billion guesses/sec): Represents attacks on stolen password hashes using powerful computers. This is common when databases are breached.
Massive Cracking (100 billion guesses/sec): Represents attacks using specialized hardware like GPU clusters or dedicated password-cracking rigs used by sophisticated attackers.
Password Entropy Explained
Entropy measures password randomness in bits. Each bit doubles the number of possible combinations. A password with 40 bits of entropy has 2^40 (over 1 trillion) possible combinations. Generally, 50+ bits is acceptable, 70+ bits is strong, and 90+ bits is excellent. Our checker calculates entropy based on character set size and password length.
Common Attack Methods
- Brute Force: Trying every possible combination systematically
- Dictionary Attack: Testing common words and phrases from wordlists
- Credential Stuffing: Using leaked passwords from other breaches
- Rainbow Tables: Pre-computed hash tables for quick password lookup
- Social Engineering: Guessing passwords based on personal information
- Keylogging: Recording keystrokes to capture passwords directly
How to Improve Your Password Strength
1. Increase Length: Add more characters - each character exponentially increases security. Aim for 16+ characters for critical accounts.
2. Add Character Variety: Mix uppercase, lowercase, numbers, and symbols to expand the character set and increase entropy.
3. Avoid Patterns: Don't use sequential characters, repeated patterns, or keyboard walks like "qwertyuiop".
4. Use Random Generation: Let a password generator create truly random passwords instead of trying to think of them yourself.
5. Consider Passphrases: Use multiple random words for better memorability while maintaining high security.
When to Check Password Strength
- Before setting a new password for important accounts
- When evaluating existing passwords for security audits
- After creating a password manually to verify its strength
- When teaching others about password security
- To understand why certain passwords are rejected by systems
- When comparing different password strategies
Frequently Asked Questions
Is it safe to check my password here?
Yes, completely safe. All analysis happens locally in your browser using JavaScript. Your password never leaves your device or gets sent to any server.
What's a good password strength score?
Aim for 80+ points for strong passwords. Scores of 60-79 are acceptable for low-risk accounts, while critical accounts should have 90+ point passwords.
Why does my long password show as weak?
Length alone isn't enough. If your password contains common words, patterns, or lacks character variety, it may still be vulnerable to dictionary or pattern-based attacks.
How often should I check my passwords?
Check passwords when creating them and periodically review your important account passwords every 3-6 months to ensure they meet current security standards.