Password Strength Checker

This Password Strength Checker evaluates your password in real-time, giving you instant feedback on its security level. The analysis runs entirely in your browser — your password is never sent to any server or stored anywhere.

The strength score is calculated based on 5 factors: length, character variety (uppercase, lowercase, numbers, symbols), and absence of repetitive patterns. Each factor contributes to the overall score, displayed as a color-coded bar from Very Weak (red) to Very Strong (green).

Entropy is the most mathematically precise measure of password strength. It's calculated based on the character pool size and password length: entropy = length × log₂(pool size). A 12-character password using all character types has about 79 bits of entropy — considered very strong.

The crack time estimate assumes an attacker using modern GPU hardware attempting 1 billion guesses per second. Modern password hashing algorithms like bcrypt, scrypt, or Argon2 slow this down dramatically — but not all sites use them. Aim for passwords that would take centuries to crack.

The 7-point security checklist covers: minimum length (8 characters), recommended length (12 characters), uppercase letters, lowercase letters, numbers, special characters, and the absence of repeating character patterns (like "aaa"). Meeting all 7 criteria significantly reduces the risk of your password being cracked.

You may also find our Password Generator, Hash Generator, and Text Encrypt / Decrypt helpful.