Credit Card Validator

1. Enter a card number — Type or paste a credit card number in the input field. Spaces and dashes are handled automatically.
2. Instant validation — The card is validated in real-time using the Luhn algorithm. Valid/invalid status updates as you type.
3. View card details — See the card issuer (Visa, Mastercard, American Express, Discover, etc.), card number length, and IIN/BIN prefix.
4. Try examples — Click the Example button to test with valid and invalid sample card numbers.

All validation is performed 100% client-side in your browser. No card data is sent to any server.

The Luhn algorithm (also known as Luhn formula or modulus 10 algorithm) is a simple checksum formula used to validate a variety of identification numbers, most notably credit card numbers. It was created by IBM scientist Hans Peter Luhn and is now in the public domain.

Starting from the rightmost digit (excluding the check digit), every second digit is doubled. If doubling results in a number greater than 9, the digits are added together (or the product minus 9). The sum of all digits must be divisible by 10 for the number to be valid.

This algorithm can detect single-digit errors and most adjacent digit transpositions, but it is not a cryptographic hash and should not be used for security purposes.