Password Strength Checker

A password strength checker is a security tool that analyzes passwords in real time and provides detailed feedback on their strength. It evaluates multiple criteria including length, character variety, and the presence of common patterns to determine how resistant a password is to brute-force and dictionary attacks.

Our free online password strength checker provides a comprehensive analysis including a strength score from 0 to 100, a visual strength meter with color coding (red for weak, orange for fair, yellow for good, green for strong), a detailed criteria checklist showing which security requirements are met, and an estimated crack time based on the password's entropy and modern computing power.

The tool checks for lowercase letters, uppercase letters, numbers, special characters, minimum length requirements, and common password patterns like "password", "123456", and "qwerty". Each criterion contributes to the overall score, giving you actionable insights on how to improve your password. The estimated crack time calculation assumes an attacker capable of 10 billion guesses per second, which reflects current GPU-accelerated cracking capabilities.

All password analysis happens entirely in your browser. Your password is never transmitted to or stored on any server, making this tool completely safe for checking even your most sensitive passwords.

1. Enter a password — Type or paste a password into the input field. The analysis updates in real time as you type.
2. Check the strength meter — The colored progress bar shows the overall strength from Weak (red) to Strong (green).
3. Review the score — The numerical score (0-100) gives you a precise measure of password strength.
4. Check the estimated crack time — See how long it would take an attacker to crack your password by brute force.
5. Review the criteria checklist — Each criterion shows a green checkmark or red cross, telling you exactly what to improve.
6. Improve your password — Add missing character types, increase length, and avoid common patterns to boost your score.

The password strength score is calculated from three components:

Length Score (0-40 points): 4-7 characters = 10 points, 8-11 characters = 20 points, 12-15 characters = 30 points, 16+ characters = 40 points.

Character Variety (0-40 points): 10 points each for lowercase letters, uppercase letters, numbers, and special characters.

Pattern Avoidance (0-20 points): 20 points if the password does not contain any common patterns from a list of frequently used passwords.

Crack Time Estimation: Based on the formula: combinations = charset_size ^ length, divided by 10 billion guesses per second. The charset size is calculated from the types of characters present (26 for lowercase, 26 for uppercase, 10 for digits, 33 for special characters).