Credit Card Validator

Credit card validation uses the Luhn algorithm, a checksum formula that validates card numbers mathematically. The algorithm applies modulo arithmetic to detect single-digit errors and most adjacent digit transpositions. It works by doubling every second digit from right to left, summing all digits, and checking if the total is divisible by 10, making it highly effective for catching input mistakes.

Our validator operates entirely client-side in your browser. No credit card information is transmitted to servers, stored, or logged anywhere. All validation happens locally using JavaScript, ensuring complete privacy and security of your sensitive data. We recommend using test numbers for development purposes rather than real card information.

The validator detects major card types including Visa (starting with 4), Mastercard (starting with 5), American Express (starting with 34 or 37), Discover (starting with 6), Diners Club, JCB, and other international card brands. Detection is based on IIN (Issuer Identification Number) ranges and follows industry standards for card number patterns.

The Luhn algorithm, also known as the "modulus 10" algorithm, is a checksum formula used to validate credit card numbers. Created by IBM scientist Hans Peter Luhn, it catches about 70% of single-digit errors and most adjacent digit transpositions. While highly effective for detecting input errors, it doesn't verify if a card is active, has sufficient funds, or belongs to a real account.

This tool is designed for educational purposes and development testing only. For actual payment processing, use certified payment gateways and processors that comply with PCI DSS standards. Never handle real credit card data without proper security certifications, compliance measures, and secure infrastructure. Real payment processing requires authorization from card networks and banking partners.

Test credit card numbers are specifically designed for development and testing purposes. They pass Luhn validation but are not associated with real accounts and cannot be used for actual transactions. Major payment processors like Stripe, PayPal, and Square provide these numbers for safely testing payment integrations without risking real financial data or transactions.

Validation checks if a credit card number follows the correct format and passes algorithmic tests like Luhn. Verification confirms the card is real, active, and belongs to the cardholder by contacting the issuing bank. Our tool performs validation only - it cannot verify if a card is genuine, active, or has available credit. Real verification requires secure connections to banking networks.

No, this tool cannot detect stolen or fraudulent cards. It only validates the mathematical correctness of card numbers and basic format checks. Fraud detection requires real-time verification with card issuer databases, behavioral analysis, and sophisticated security systems that only banks and authorized payment processors have access to. Never rely on format validation alone for security purposes.

CVV (Card Verification Value) codes are 3-4 digit security codes that help verify card-not-present transactions. Our tool validates CVV format and length (3 digits for most cards, 4 for American Express) but cannot verify the actual CVV value. Real CVV verification requires secure communication with the card issuer's systems and is only available to authorized merchants and payment processors.

Developers should implement client-side validation for user experience but never rely on it for security. Always use server-side validation, secure HTTPS connections, and PCI DSS compliant systems. Consider using established payment processors rather than handling credit card data directly. Implement proper error handling, data sanitization, and never log or store sensitive card information unless absolutely necessary and properly secured.