Free Tool

Password Strength Checker

Free online password strength checker. No sign-up, no installation. Runs entirely in your browser.

Enter Password

🔒 Your password never leaves your device. All calculations happen locally in your browser.

Strength Level

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0 / 100

Statistics

Characters

Entropy Bits

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Time to Crack

What is Password Strength?

Password strength measures how resistant a password is to being guessed or cracked through automated attacks. A strong password is difficult to predict and uses a combination of character types and sufficient length.

This checker analyzes your password against multiple factors:

Length: Longer passwords are exponentially harder to crack
Character Variety: Mix of uppercase, lowercase, numbers, and symbols increases complexity
Pattern Detection: Identifies keyboard walks, sequential characters, and common words
Entropy: Measures the randomness and unpredictability of your password

How to Use This Tool

Type or paste a password into the input field above
Watch the strength meter update in real-time as you type
Review the feedback and statistics to understand your password's security
Follow the suggestions to improve your password strength if needed
Remember: Never use the same password across multiple websites

Understanding Strength Levels

Very Weak (0-19)

Extremely vulnerable to attack. Too short or lacks variety.

Weak (20-39)

Below minimum security standards. Add length or character types.

Fair (40-59)

Acceptable but not optimal. Could be improved further.

Strong (60-79)

Good security level. Suitable for most accounts.

Very Strong (80-100)

Excellent security. Highly resistant to brute-force attacks. Best for sensitive accounts.

Frequently Asked Questions

How does this tool estimate time to crack?

The tool estimates time to crack based on offline attacks, assuming 1 billion guesses per second. This is a conservative estimate. Online attacks (against websites with rate limiting) would be much slower. The actual time depends on the attacker's resources and the security measures in place.

Is my password sent to any server?

No. This tool runs entirely in your browser. Your password is never sent anywhere. All calculations happen locally on your device. You can even disconnect from the internet and the tool will continue to work.

What makes a password strong?

A strong password typically has: at least 12 characters, a mix of uppercase and lowercase letters, numbers, and special symbols, no dictionary words or keyboard patterns, and no personal information (names, birthdays). Avoid using predictable substitutions like "P@ssw0rd" which contains common patterns.

Should I use the same password everywhere?

Absolutely not. Using the same password across multiple websites means that if one service is compromised, attackers can access all your accounts. Use unique, strong passwords for each important account. Consider using a password manager to securely store your passwords.

What's the difference between entropy and strength?

Entropy measures the number of possible combinations in your password (in bits). A password with higher entropy is harder to crack. Strength is a simplified rating (Very Weak to Very Strong) that considers entropy, length, and patterns. High entropy doesn't guarantee high strength if the password contains predictable patterns.

Can I use spaces and special Unicode characters?

Most websites only accept ASCII characters (letters, numbers, and basic symbols). Some advanced systems support spaces and special Unicode characters, which would increase entropy. Always check your service's password requirements. Spaces and unique characters can significantly improve password strength when supported.