Credit Card Validator
Validate Credit Card Number Format Using the Luhn Algorithm
| Credit Card Type | Credit Card Number |
|---|---|
| American Express | 371449635398431 |
| Diners Club | 30569309025904 |
| Discover | 6011111111111117 |
| JCB | 3530111333300000 |
| MasterCard | 5555555555554444 |
| Visa | 4916592289993918 |
What Is a Credit Card Validator?
A credit card validator checks whether a credit card number is format-valid by applying the Luhn algorithm (also known as the modulo-10 or mod-10 algorithm). This is a mathematical checksum formula used to validate identification numbers, including credit card numbers, IMEI numbers, and government ID numbers.
Important: Format Validation Only
This tool validates the format of a card number, not whether the card exists or has funds. It checks that the number follows the correct length, BIN prefix, and Luhn check digit rules. It does not verify whether the card is active, issued by a bank, or has available credit.
How the Luhn Algorithm Works
- Starting from the rightmost digit (excluding the check digit), double every second digit.
- If doubling results in a number greater than 9, subtract 9 from the result.
- Sum all the digits (doubled and non-doubled).
- If the total modulo 10 equals 0, the number is valid according to the Luhn algorithm.
What the Validator Checks
- Luhn algorithm - Whether the check digit is mathematically valid.
- Card number length - Whether the number has the correct length for its card type.
- BIN/IIN prefix - Whether the first digits match a known card issuer.
- Card type - Identifies the card type (Visa, Mastercard, Amex, Discover) based on the prefix.
When to Use the Validator
- Form testing - Verify that your payment form correctly validates card numbers.
- Data quality - Check card number data for typos or formatting errors.
- Education - Learn how the Luhn algorithm and credit card validation work.
- Development - Test card number validation logic in your application.
Format validity does not imply that a card is active, real, or authorized.
AI Overview
A credit card validator checks whether a card number is format-valid using the Luhn algorithm. It verifies the check digit, number length, BIN prefix, and identifies the card type. This tool validates format only - it does not check whether a card exists, is active, or has funds. It is used for form testing, data quality checks, and education.
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