Credit Card Validator

Free Credit Card Validator — Luhn Check & Card Type Detection

For development and educational purposes only. Building payment forms and checkout flows requires client-side credit card number validation before sending data to the server. This free Credit Card Validator checks any card number against the Luhn algorithm checksum and identifies the card type (Visa, Mastercard, Amex, Discover, and more) based on the IIN prefix pattern — giving developers a quick way to test validation logic without handling real card data.

Enter any card number (with or without spaces/dashes) and the validator instantly shows whether it passes Luhn validation, identifies the card network, indicates the expected card number length, and confirms the CVV digit count. This is the same logic implemented in payment form JavaScript libraries.

Note: Passing Luhn validation does not mean the card is real, active, or has available funds. The Luhn check only verifies the mathematical checksum. Payment authorization requires actual processing through a payment gateway.

The Luhn Algorithm Explained

Step 1. Starting from the last digit (check digit), move left. Double every second digit.

Step 2. If doubling produces a two-digit number (10 or greater), subtract 9 from the result (equivalent to summing the two digits).

Step 3. Sum all digits (doubled-and-adjusted plus unchanged).

Step 4. If the total sum modulo 10 equals 0, the number passes Luhn validation. Example: 4111111111111111 sums to 40 (passes). 4111111111111112 sums to 41 (fails).

Related Tools

• Credit Card Generator – Generate test card numbers for development.
• Password Strength Checker – Check password security.

Frequently Asked Questions