How do I check my password strength?

Enter your password in our password strength checker and it will instantly analyze the entropy (randomness), character diversity, length, and common patterns. You'll see a strength score (0-100), estimated crack time, and specific tips to improve your password. All analysis happens in your browser — your password is never sent to any server.

Is it safe to type my password into this tool?

Yes, completely safe. Our password strength calculator runs entirely in your browser using client-side JavaScript. Your password is never transmitted over the internet, never stored, and never sent to any server. You can verify this by disconnecting from the internet and the tool will still work perfectly.

What makes a strong password?

A strong password has: 1) Length of 12+ characters (most important factor), 2) Mix of uppercase, lowercase, numbers, and symbols, 3) No dictionary words or common patterns, 4) No personal information, 5) High entropy (randomness). Our password strength tester checks all these factors and gives you a comprehensive score.

What is password entropy?

Password entropy measures the randomness/unpredictability of a password in bits. It's calculated as: Entropy = Length × log₂(CharacterPoolSize). Higher entropy = harder to crack. 40 bits is weak, 60 bits is reasonable, 80+ bits is strong, 100+ bits is very strong. Our password entropy calculator shows this score instantly.

How long would it take to crack my password?

Crack time depends on the attack method and computing power. Our password crack time calculator estimates time based on 10 billion guesses/second (modern GPU cluster). A 6-character lowercase password: ~5 minutes. An 8-character mixed password: ~8 hours. A 12-character mixed password: ~34,000 years. Length is your best defense.

Are passphrases better than passwords?

Yes, passphrases (4+ random words like 'correct-horse-battery-staple') are generally better because they're long (high entropy) and memorable. A 4-word passphrase from a 7,776-word list has ~51 bits of entropy. Adding a number and symbol pushes it to 60+ bits. The key is using truly random words, not a meaningful phrase.

Should I use a password manager?

Absolutely. Password managers generate and store unique, strong passwords for every account. You only need to remember one master password. This solves the biggest security problem: password reuse. Even the strongest password is useless if it's reused and one site gets breached. Popular options: 1Password, Bitwarden, KeePass.

What is the minimum recommended password length?

Security experts recommend at least 12 characters, with 16+ being ideal. NIST (National Institute of Standards and Technology) recommends a minimum of 8 characters, but longer is always better. Each additional character multiplies the number of possible combinations. A 16-character password is billions of times harder to crack than an 8-character one.

Password Strength Calculator

Our password strength calculator analyzes your password's security by measuring entropy (randomness), character diversity, length, and common pattern detection. It estimates how long it would take to crack using brute force attacks and provides actionable tips to strengthen your passwords. Privacy-first: all analysis happens in your browser — your password never leaves your device.

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calendar_today Updated: April 2026

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shield 100% Private — your password never leaves your browser. All analysis is done locally.

Enter Password

Strength No Password

Character Analysis

close 8+ characters

close Uppercase (A-Z)

close Lowercase (a-z)

close Numbers (0-9)

close Symbols (!@#$)

close 12+ characters

Score lock_open

/100

Time to Crack timer

Instant

At 10 billion guesses/second

Entropy

0 bits

Pool Size

0 chars

Details

Length 0 characters

Possible Combinations 0

Character Types 0 of 4

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Password Security Analysis:

Tip: Use 12+ characters with a mix of types for strong security
Best practice: Use a unique password for every account
Consider: A passphrase like 'correct-horse-battery-staple' is strong AND memorable

Your password never leaves your browser — all analysis is done locally.

lightbulb Tips

•12+ characters is the minimum recommendation
•Length matters more than complexity
•Never reuse passwords across sites
•Use a password manager for best security

How to Use This Calculator

password

Enter Your Password

Type or paste a password into the input field. It's 100% private — nothing is sent to any server.

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Review Strength Score

See the strength rating, entropy bits, and estimated time to crack with brute force attacks.

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Improve Your Password

Follow the personalized tips to make your password stronger. Aim for 80+ bits of entropy.

The Formula

Password entropy measures the randomness and unpredictability of a password. It's calculated as the password length multiplied by the log base 2 of the character pool size. A password using lowercase (26) + uppercase (26) + digits (10) + symbols (33) = 95 possible characters. Each additional character exponentially increases the number of possible combinations, making the password harder to crack.

Entropy = L × log₂(R)

lightbulb Variables Explained

L Password length (number of characters)
R Character pool size (possible characters per position)
Entropy Password strength in bits — higher is better

tips_and_updates Pro Tips

Length is the most important factor — aim for 12+ characters minimum, 16+ is ideal

Use a mix of uppercase, lowercase, numbers, and symbols for maximum entropy

Passphrases (random words strung together) are both strong and memorable: 'correct-horse-battery-staple'

Never reuse passwords across accounts — use a password manager instead

Avoid personal information (names, birthdays, pet names) that can be guessed

Common substitutions (@ for a, 3 for e) add minimal security — attackers know these tricks

Enable two-factor authentication (2FA) for an additional layer of security beyond passwords

Check How Strong Your Password Is — Free & Private

Our password strength calculator analyzes your password's security in real-time, entirely in your browser. See entropy score, estimated crack time, and get actionable tips to create stronger passwords. Your password never leaves your device.

Password Strength Checker with Entropy Analysis

Password entropy is the gold standard for measuring password strength. Our password entropy calculator shows exactly how many bits of randomness your password contains. More entropy bits means exponentially more combinations an attacker must try. Aim for 80+ bits for important accounts.

Password Crack Time Calculator

How long would it take to crack your password? Our brute force time calculator estimates crack time based on modern GPU clusters (10 billion guesses/second). See the dramatic difference between a 6-character password (minutes) and a 16-character password (centuries).

How to Create a Strong Password

The best passwords combine length with complexity. Use 12+ characters mixing uppercase, lowercase, numbers, and symbols. Or use a passphrase of 4+ random words. Avoid personal info, common words, and predictable patterns. Our password strength tester shows exactly what makes your password strong or weak.

Frequently Asked Questions

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