Password Strength Checker

How long would it take to crack your password?
Test entropy and security with our 100% Client-Side tool.

Check Your Password

Secure: Processing happens in your browser.

StrengthEnter Password

Requirements

At least 12 characters

Uppercase letter (A-Z)

Lowercase letter (a-z)

Number (0-9)

Symbol (!@#$%)

Common Use Cases

🛡️

Audit Security

Check if your current passwords meet modern security standards (NIST guidelines).

🎓

Education

Learn how adding numbers, symbols, and length drastically increases crack time.

🔑

Policy Testing

Test password policies (e.g. "min 8 chars") to see if they actually result in strong passwords.

🧠

Entropy Check

Understand the mathematical complexity of your phrase in "bits" of entropy.

How it Works

This tool analyzes your password based on "Entropy" — a measure of unpredictability or randomness measured in bits.

Type a Password: Enter any string in the input field. Don't worry, the analysis happens locally in your browser.
Instant Feedback: The meter will update in real-time, showing a score from "Very Weak" to "Excellent".
Check Requirements: See exactly what is missing (e.g., numbers, special symbols, or length) to improve your score.

Security Note: We strictly follow a client-side only policy. The password you type never leaves your device and is never sent to our servers. Usage is anonymous.

Validating Passwords in Code

Implementing password checks in your app? Here is how to use Regex to validate complexity in different languages.

JavaScriptRegex

function validatePassword(password) {
  // Min 8 chars, 1 letter, 1 number
  const regex = /^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{8,}$/;
  return regex.test(password);
}

console.log(validatePassword("Pass1234")); // true

Pythonre module

import re

def validate_password(password):
    if len(password) < 8:
        return False
    if not re.search(r"[a-z]", password):
        return False
    if not re.search(r"[A-Z]", password):
        return False
    if not re.search(r"[0-9]", password):
        return False
    return True

PHPpreg_match

$password = 'Secret123!';
$uppercase = preg_match('@[A-Z]@', $password);
$lowercase = preg_match('@[a-z]@', $password);
$number    = preg_match('@[0-9]@', $password);

if(!$uppercase || !$lowercase || !$number || strlen($password) < 8) {
    echo 'Password is weak';
}

JavaString matches

String password = "MySecurePassword1";
// At least one digit, one lower, one upper, 8-20 chars
String pattern = "((?=.*\\d)(?=.*[a-z])(?=.*[A-Z]).{8,20})";

System.out.println(password.matches(pattern));

Frequently Asked Questions

What makes a password strong?

Length is the most critical factor. A 15-character password made of random letters is often stronger than an 8-character password with symbols. Ideally, use a mix of uppercase, lowercase, numbers, and symbols, and aim for at least 12 characters.

Is it safe to type my password here?

Yes. This tool runs 100% in your browser using JavaScript. Your keystrokes are never sent over the internet. However, for maximum security, we recommend never typing your actual banking passwords into any online checker. Use this to test variations or new ideas.

What is entropy?

Entropy (in bits) relates to the number of combinations an attacker would need to try to guess your password. Each bit doubles the difficulty. 60+ bits is okay, 100+ is excellent.

How can I remember strong passwords?

Use passphrases (3-4 random words) like "correct-horse-battery-staple". Or better yet, use a Password Manager to generate and store random passwords for you.

Should I change my password often?

NIST guidelines now recommend simpler policies: change passwords only if compromised. Frequent forced changes often lead to weaker passwords (e.g., Spring2023!, Summer2023!).