rand-verification-code

rand-verification-code

A lightweight, flexible JavaScript library for generating random verification codes with customizable character sets and security options.

Features

• 🎲 Cryptographically secure random generation (when available)
• 🔧 Highly configurable character sets
• 🚫 Option to avoid ambiguous characters (0/O, 1/l/I, etc.)
• 📦 Zero dependencies
• 🌐 Works in Node.js and browsers
• 💪 TypeScript-friendly

Installation

npm install rand-verification-code

Usage

Basic Usage

const { generateVerificationCode } = require('rand-verification-code');

// Generate a 6-character code with digits and uppercase letters (default)
const code = generateVerificationCode();
console.log(code); // Example: "A3K9P2"

Custom Configuration

// 8-digit numeric code
const numericCode = generateVerificationCode({
  length: 8,
  digits: true,
  uppercase: false
});
console.log(numericCode); // Example: "48273956"

// Alphanumeric with lowercase
const mixedCode = generateVerificationCode({
  length: 10,
  digits: true,
  lowercase: true,
  uppercase: true
});
console.log(mixedCode); // Example: "Kj8mN3pQr2"

// Include symbols
const strongCode = generateVerificationCode({
  length: 12,
  digits: true,
  uppercase: true,
  lowercase: true,
  symbols: true
});
console.log(strongCode); // Example: "aB3#xY9@mK!p"

// Custom character set
const customCode = generateVerificationCode({
  length: 6,
  charset: 'ABCDEF0123456789' // Hexadecimal
});
console.log(customCode); // Example: "A3F90B"

API

generateVerificationCode([options])

Generates a random verification code string.

Options

Option	Type	Default	Description
length	number	6	Length of the generated code
digits	boolean	true	Include digits (0-9)
lowercase	boolean	false	Include lowercase letters (a-z)
uppercase	boolean	true	Include uppercase letters (A-Z)
symbols	boolean	false	Include symbols (!@#$%^&*...)
avoidAmbiguous	boolean	true	Avoid ambiguous characters (0, O, o, 1, l, I, etc.)
charset	string	undefined	Custom character set (overrides all other character options)

Returns

Returns a string containing the randomly generated verification code.

Throws

• TypeError - If length is not a positive integer
• Error - If the character pool is empty (no character types enabled)

Examples

Email Verification Code

const emailCode = generateVerificationCode({
  length: 6,
  digits: true,
  uppercase: true,
  lowercase: false,
  avoidAmbiguous: true
});
// Example: "A3K9P2"

SMS Verification Code

const smsCode = generateVerificationCode({
  length: 4,
  digits: true,
  uppercase: false,
  lowercase: false
});
// Example: "7392"

Strong Password Reset Token

const resetToken = generateVerificationCode({
  length: 32,
  digits: true,
  uppercase: true,
  lowercase: true,
  symbols: true,
  avoidAmbiguous: false
});
// Example: "aB3#xY9@mK!pQ2$wR5^nT8&vU7*zC4"

Security

This library uses crypto.randomBytes() when available (Node.js environment) for cryptographically secure random number generation. In browser environments or when crypto is unavailable, it falls back to Math.random().

Note: For security-critical applications, ensure you're running in an environment where crypto.randomBytes() is available.

Browser Support

This library works in all modern browsers and Node.js environments. When using in browsers, make sure to bundle it with your preferred build tool (Webpack, Rollup, etc.).

License

MIT

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Author

Niroshan Vijayarasa

Support

If you encounter any issues or have questions, please file an issue on the GitHub repository.