Password Strength Checker

About Password Strength Checker

Password strength is a measure of how resistant a password is to guessing and brute-force attacks. Strong passwords are essential for protecting online accounts, as weak passwords are one of the most common causes of security breaches. A strong password typically combines length, complexity, and unpredictability.

Length is the single most important factor in password strength. Each additional character exponentially increases the number of possible combinations. A 12-character password with mixed character types has approximately 2^72 possible combinations — making brute-force attacks computationally infeasible. Modern guidelines recommend a minimum of 12-16 characters.

Character diversity strengthens passwords by expanding the character set an attacker must test. Using uppercase letters, lowercase letters, digits, and special characters creates a search space of ~95 characters per position. However, forcing specific character requirements can make passwords harder to remember without proportionally increasing security against modern attack methods.

Common password weaknesses include: using dictionary words, personal information (names, birthdays), sequential characters (12345, qwerty), reuse across multiple sites, and short passwords under 8 characters. Attackers use dictionary attacks, rainbow tables, and credential stuffing to exploit these weaknesses. A unique, randomly generated password for each service is the gold standard.

This tool analyzes passwords entirely in your browser — no data is ever sent to a server. The strength assessment considers length, character diversity, and common patterns. For maximum security, use a password manager to generate and store strong, unique passwords for every account, and enable two-factor authentication wherever possible.