A customizable password strength checker and generator
npm install password-strength-testerbash
npm install password-strength-tester
`
Usage
`javascript
const { check, generateStrongPassword } = require("password-strength-tester");
// Check password strength
const strengthResult = check("MyPassword123!");
console.log(strengthResult);
// Output: { strength: 'Strong', score: 85 }
// Generate a password with default settings
const password = generateStrongPassword();
console.log(password);
// Output: "Kx7#mN!9p"
`
Password Strength Checking
The check function evaluates passwords based on multiple criteria:
`javascript
const result = check("YourPassword123!");
console.log(result);
`
Returns an object with:
- strength: Text representation of password strength
- score: Numerical score (0-100)
- suggestion: Generated password suggestion (only for weak passwords)
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- Very Strong (90-100)
- Strong (70-89)
- Medium (50-69)
- Weak (30-49)
- Very Weak (0-29)
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- Length (minimum and extra points)
- Character variety
- Sequential characters
- Common patterns
- Mixed character types bonus
Password Generation
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`javascript
// Default configuration (9 characters)
const password = generateStrongPassword();
// Custom length
const longPassword = generateStrongPassword({ length: 16 });
`
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`javascript
const customPassword = generateStrongPassword({
length: 12,
charCounts: {
upper: 3, // uppercase letters
lower: 4, // lowercase letters
numbers: 3, // numeric digits
special: 2, // special characters
},
});
`
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`typescript
interface PasswordConfig {
length?: number; // Total length (default: 9)
charCounts?: {
upper?: number; // Uppercase count (default: 2)
lower?: number; // Lowercase count (default: 3)
numbers?: number; // Numbers count (default: 2)
special?: number; // Special chars count (default: 2)
};
}
`
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`javascript
// Only uppercase and numbers
const uppercaseNumbers = generateStrongPassword({
length: 10,
charCounts: {
upper: 5,
lower: 0,
numbers: 5,
special: 0,
},
});
// Only lowercase letters
const lowercaseOnly = generateStrongPassword({
length: 8,
charCounts: {
upper: 0,
lower: 8,
numbers: 0,
special: 0,
},
});
// Extra special characters
const specialHeavy = generateStrongPassword({
length: 12,
charCounts: {
special: 4,
},
});
`
Character Sets
Default character sets used for generation:
- Uppercase: A-Z
- Lowercase: a-z
- Numbers: 0-9
- Special: !@#$%^&\*()\_+-=[]{}|;:,.<>?
Error Handling
The module throws errors for invalid inputs:
`javascript
try {
const password = generateStrongPassword({
length: 5,
charCounts: {
upper: 10, // Error: exceeds total length
},
});
} catch (error) {
console.error(error.message);
// "Total character counts cannot exceed password length"
}
`
TypeScript Support
Full TypeScript support with type definitions included:
`typescript
import { check, generateStrongPassword } from "password-strength-tester";
interface PasswordResult {
strength: string;
score: number;
suggestion?: string;
}
`
Contributing
Contributions are welcome! Please feel free to submit a Pull Request.
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1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature`)