Credit Card Number Validator

1. Enter a credit card number in the input field (spaces and dashes are ignored).
2. Click "Validate" or press Enter.
3. See the detected card type (Visa, Mastercard, Amex, Discover) and whether the number passes Luhn validation.
4. Try the example test card numbers to see the tool in action.

About the Luhn Algorithm

The Luhn algorithm is a simple checksum formula used to validate identification numbers such as credit card numbers, IMEI numbers, and Canadian Social Insurance Numbers. It was created by Hans Peter Luhn in 1954 and is designed to protect against accidental errors, not malicious attacks. Most credit card companies use this algorithm as a first-pass check before processing transactions.