Credit card validator

Check credit card numbers with the Luhn algorithm and identify matching card networks.

Credit card number

Check credit card numbers with the Luhn algorithm and identify matching card networks.

Validation result

Review the detected brand, supported length, Luhn check, and CVC details for the entered number.

Enter a card number to start validation.

What is credit card validation?

Credit card validation is a process to check if a card number is potentially valid before processing a transaction. It uses the Luhn algorithm and card brand identification to verify the format.

Luhn algorithm

The Luhn algorithm (also known as Mod 10) is a checksum formula used to validate identification numbers. Here's how it works:

  1. Starting from the rightmost digit, double every second digit
  2. If doubling results in a number greater than 9, subtract 9 from the result
  3. Sum all digits. If the total is divisible by 10, the number is valid

Supported card brands

Card brands are identified by their BIN (Bank Identification Number) or IIN (Issuer Identification Number), which are the first few digits of the card number.

  • Visa: 4 · 13, 16, 19
  • Mastercard: 51-55, 2221-2720 · 16
  • American Express: 34, 37 · 15
  • Discover: 6011, 65, 644-649, 622126-622925 · 16, 19
  • JCB: 3528-3589 · 16, 17, 18, 19
  • UnionPay: 62 · 16, 17, 18, 19
  • Diners Club: 36, 38, 39, 300-305 · 14, 16, 19

How to use

Enter a card number to format it automatically and review the detected brand, supported length, Luhn check, and expected CVC length. Copy the normalized number from the result when available.