Password Strength Checker
Check how strong your password is. Get instant feedback on length, complexity, and estimated crack time.
About Password Strength Checker
Analyze your password strength with our free online tool. Get detailed feedback on length, character diversity, common patterns, and estimated time to crack. All analysis happens in your browser — your password is never sent to any server.
What Is Password Strength?
Password strength measures how resistant a password is to guessing and brute-force attacks. A strong password combines sufficient length, character variety (uppercase, lowercase, numbers, and symbols), and unpredictability. Weak passwords — short ones, dictionary words, or common patterns like "123456" — can be cracked in seconds by modern hardware. Password strength is often expressed as entropy, measured in bits, which quantifies how many guesses an attacker would need on average to crack it.
How to Use This Tool
Type or paste a password into the input field above to get instant feedback. The tool evaluates your password across several criteria: length, character diversity, use of common patterns, dictionary words, and repeated sequences. You will see a strength rating from very weak to very strong, along with an estimated time to crack. Use this feedback to improve your passwords before using them on real accounts.
Why Password Security Matters
Compromised passwords are the leading cause of data breaches. Attackers use techniques like credential stuffing (trying leaked passwords on other sites), brute-force attacks (systematically trying every combination), and dictionary attacks (testing common words and phrases). A single weak password can expose your email, banking, social media, and other accounts. Using strong, unique passwords for each service is one of the most effective steps you can take to protect your digital identity.
How Password Cracking Works
Modern password cracking uses GPUs that can test billions of combinations per second. Attackers start with the most likely guesses: common passwords, dictionary words, and known patterns. They then move to brute-force methods, trying every possible combination of characters. Longer passwords with mixed character types exponentially increase the number of possible combinations, making them far more resistant to these attacks. A 12-character password with mixed characters can take centuries to crack, while an 8-character lowercase password can fall in minutes.
Tips for Creating Strong Passwords
Use at least 12 characters, combining uppercase letters, lowercase letters, numbers, and symbols. Avoid personal information like birthdays or pet names. Do not reuse passwords across different accounts. Consider using a passphrase — a series of random words strung together — which is both strong and easier to remember. For best security, use a password manager to generate and store unique passwords for every account.