A Developer's Guide to the Credit Card Validator

The Credit Card Validator is a tool designed for developers and testers to check the format and validity of credit card numbers during the development process. It performs several checks to ensure a number is plausible without ever touching a payment network.

Disclaimer: This tool is for development and testing purposes only. Do not use real credit card numbers. All validation is performed locally in your browser and is not sent over the network.

Features

• Luhn Algorithm Check: The primary validation is the Luhn algorithm (also known as the "modulus 10" or "mod 10" algorithm), which is a standard checksum formula used to validate a variety of identification numbers.
• Comprehensive Validation: It checks not just the card number, but also the expiration date format and the CVV length based on the card type.
• Card Type Identification: The tool automatically identifies the card brand (e.g., Visa, Mastercard, Amex) based on the number's prefix.
• Real-time Feedback: Get instant results on whether the number, expiration date, and CVV are valid, potentially valid (incomplete), or invalid.

How to Use

1. Enter Card Details: Type a test credit card number, its expiration date (in MM/YY format), and its CVV into the respective fields.
2. Click Validate: Press the "Validate" button.
3. Review Results: A results card will appear below, showing you:
   • The validation status for the card number, expiration date, and CVV.
   • The identified card type.