Password Strength Checker
Test how strong your password is. Get crack time estimates and tips to improve your security.
Generate a Strong Passphrase
Click the button to generate a random, easy-to-remember passphrase.
About Password Strength
A strong password is your first line of defense against unauthorized access to your accounts. This tool evaluates your password based on several factors:
- Length - Longer passwords are exponentially harder to crack. Aim for 12+ characters minimum.
- Character Diversity - Using uppercase, lowercase, numbers, and symbols increases the number of possible combinations.
- Unpredictability - Avoiding common words, patterns, and personal information makes brute-force attacks impractical.
- Uniqueness - Never reuse passwords across multiple accounts.
How Password Cracking Works
Attackers use several techniques to crack passwords. Understanding these methods helps you create passwords that resist them:
- Brute Force - Trying every possible combination. Modern hardware can attempt billions of combinations per second against leaked password hashes.
- Dictionary Attacks - Using lists of common words, phrases, and previously leaked passwords. This is why common passwords like "password123" are cracked instantly.
- Rule-Based Attacks - Applying common transformations to dictionary words (e.g., "p@ssw0rd" instead of "password"). Simple character substitutions provide minimal security.
- Rainbow Tables - Pre-computed tables that map hashes to passwords, effective against unsalted hashes.
The crack time estimates in this tool assume a sophisticated attacker performing 10 billion guesses per second, which represents modern GPU-based cracking capabilities.
Best Practices for Password Security
- Use a password manager - Generate and store unique, complex passwords for every account
- Enable two-factor authentication (2FA) - Even if your password is compromised, 2FA provides an additional layer of security
- Use passphrases - Random word combinations like "correct horse battery staple" are both strong and memorable
- Check for breaches - Services like Have I Been Pwned can tell you if your email has appeared in data breaches
- Update compromised passwords immediately - If a service you use is breached, change your password right away
Frequently Asked Questions
How strong is my password?
A strong password is at least 12 characters long and includes a mix of uppercase letters, lowercase letters, numbers, and symbols. It should not contain common words, personal information, or predictable patterns. Use our checker above to test yours instantly.
What makes a password secure?
A secure password has high entropy, meaning it is unpredictable and complex. Key factors include length (12+ characters), character variety, avoidance of dictionary words and patterns, and uniqueness. Passphrases of 4+ random words are both strong and memorable.
Is it safe to type my password into this tool?
Yes. This password strength checker runs entirely in your browser using JavaScript. Your password is never transmitted to our servers or any third party. You can verify this by disconnecting from the internet and confirming the tool still works.
How long would it take to crack my password?
Crack time depends on your password's length, complexity, and the attacker's resources. Our tool estimates crack time based on an attacker capable of 10 billion guesses per second. A short simple password can be cracked instantly, while a long complex one could take centuries.