Password Strength Checker

A password is only as strong as the number of possible combinations an attacker must try before guessing it correctly — and that number is determined by two variables: the length of the password and the size of the character set it draws from. An 8-character password using only lowercase letters has 26⁸ ≈ 200 billion possible combinations — which sounds impressive until you learn that modern GPU-accelerated brute-force tools can test over 100 billion combinations per second, cracking such a password in under 2 seconds. Add uppercase letters, numbers and symbols and extend to 12 characters, and the combination count explodes to 95¹² ≈ 540 quintillion — requiring hundreds of thousands of years at the same attack rate. Our password strength checker calculates this precisely: it estimates the character set, calculates entropy in bits, and translates the result into a realistic crack-time estimate using modern attack benchmarks — giving you a clear, honest picture of exactly how protected you actually are.

Understanding password strength goes hand-in-hand with generating strong passwords. Our Secure Password Generator creates cryptographically random passwords of any length and complexity — with precise control over which character sets to include. After generating a password there, paste it here to see its entropy score, estimated crack time and a full security checklist. The two tools together form a complete password security workflow: generate, verify, and deploy with confidence.

For developers working with authentication systems, it is worth noting that passwords are rarely stored in plain text — they are hashed, and often the hash itself is stored as a Base64-encoded string. Our Base64 Encoder/Decoder can help you inspect or verify these encoded credential strings — an essential skill for anyone building or auditing authentication systems and security infrastructure.