About the Credit Card Validator

This tool uses the Luhn algorithm (also known as the "modulus 10" algorithm) to validate credit card numbers and identifies the card type based on the number pattern. This is the same algorithm used by banks and credit card companies to check for valid card numbers.

How the Validation Works

The Luhn algorithm works as follows:

1. Starting from the rightmost digit and moving left, double the value of every second digit
2. If doubling results in a two-digit number, add those digits together (e.g., 8 × 2 = 16, 1 + 6 = 7)
3. Add all the resulting digits together
4. If the total is divisible by 10, the number is valid

Credit Card Number Patterns

Card Type	Number Pattern	Length	CVV/CVC
Visa	Starts with 4	13, 16, or 19 digits	3 digits
Mastercard	Starts with 51-55 or 2221-2720	16 digits	3 digits
American Express	Starts with 34 or 37	15 digits	4 digits
Discover	Starts with 6011, 622126-622925, 644-649, or 65	16 digits	3 digits
JCB	Starts with 3528-3589	16-19 digits	3 digits
Diners Club	Starts with 300-305, 36, or 38-39	14 digits	3 digits

Security & Privacy

This validation is performed entirely in your browser. No card data is transmitted, stored, or processed on our servers. This tool only checks if the card number format is valid according to the Luhn algorithm; it does not verify if the card is active, has sufficient funds, or is authorized for use.

When to Use This Tool

• Developers testing payment forms
• Verifying a credit card number before attempting a transaction
• Identifying the type of credit card from its number
• Educational purposes to understand credit card validation