The generator uses specific algorithms to create numbers that follow the format and rules of each card issuer (Visa, MasterCard, American Express, JCB). This includes using the correct starting digits, length, and applying the Luhn algorithm to ensure the numbers pass basic validity checks.


Using these numbers for testing and educational purposes is generally legal. However, it is illegal to use these numbers for fraudulent activities or to attempt real transactions. Always ensure you have permission when using these numbers in any system or application.

You can use this generator for testing purposes in your website or app development process. However, make sure to clearly indicate that the generated numbers are for testing only and cannot be used for real transactions. Always follow best practices for handling sensitive data, even when working with fake credit card numbers.