What is Password Strength Checker?
Password strength is a measure of how resistant a password is to guessing and brute-force attacks. A strong password combines length (12+ characters), character diversity (uppercase, lowercase, numbers, symbols), unpredictability (not based on dictionary words or personal info), and uniqueness (not reused across accounts). Password strength checkers calculate entropy — measured in bits — to estimate how many guesses an attacker would need to crack the password. A password with 60+ bits of entropy is considered strong against offline attacks. Modern password crackers like Hashcat can test billions of passwords per second against leaked hash databases, making password strength critically important. The best protection is using a password manager to generate and store unique, random passwords.