๐ณ Credit Card Validator
Security Notice: This tool runs entirely in your browser. No card data is stored or transmitted.
๐งช Test Card Numbers
These are valid test numbers for development purposes only:
โ Frequently Asked Questions
What is the Luhn Algorithm?
The Luhn algorithm (also known as the "modulus 10" algorithm) is a checksum formula used to validate credit card numbers. It was created by IBM researcher Hans Peter Luhn and helps detect simple errors in typing or transmission of card numbers.
How does the Luhn Algorithm work?
1. Starting from the right, double every second digit
2. If doubling results in a two-digit number, add the digits together
3. Add all the digits together
4. If the total modulo 10 equals 0, the number is valid
Which card types are supported?
This validator supports: Visa, Mastercard, American Express, Discover, JCB, Diners Club, and Maestro. Each card type has specific number patterns and lengths.
Is this tool secure?
Yes! All validation happens locally in your browser using JavaScript. No card data is sent to any server or stored anywhere. The tool is completely safe for testing.
What does validation tell me?
Validation only confirms that a card number is mathematically correct according to the Luhn algorithm. It does NOT verify if the card is active, has available credit, or belongs to a real account.
Why do some valid cards fail validation?
Some newer card types or regional cards may not be recognized. Also, virtual card numbers or some prepaid cards might use different validation rules.