💳Credit Card Validator

Validate credit card numbers using the Luhn algorithm.

Card Number

For validation purposes only. No real card processing occurs.

About Credit Card Validator

Credit Card Validator checks whether any card number passes the Luhn algorithm checksum — the mathematical formula used by all major card issuers to detect typos and invalid numbers. It also identifies the card network (Visa, Mastercard, Amex, Discover) from the number prefix.

How to Use Credit Card Validator

1
Enter the card number
Type or paste the credit card number you want to validate. Spaces and dashes are ignored automatically.
2
Run the validation
Click 'Validate' to check the number against the Luhn algorithm and identify the card network.
3
Review the result
See whether the number is mathematically valid, which card network it belongs to (Visa, Mastercard, Amex, etc.), and any format issues.

Common Use Cases

Developers validating credit card inputs on payment forms before submitting to a processor
Testing payment integrations with known valid and invalid test card numbers
Verifying that manually transcribed card numbers don't contain typos
Learning how the Luhn algorithm works with real-world examples

Frequently Asked Questions

What is the Luhn algorithm?

The Luhn algorithm is a simple checksum formula used to validate credit card numbers. It works by doubling every second digit from the right, summing all digits, and checking whether the total is divisible by 10. A valid card number always passes this check.

Does a valid Luhn checksum mean the card is real and active?

No — passing the Luhn check only means the number is mathematically valid in format. It does not verify that the card account exists, has funds, or isn't expired. Real authorization requires a payment processor.

Can I use this to validate test card numbers?

Yes — this is a common use case for developers testing payment integrations. Enter test card numbers (like Stripe's 4242 4242 4242 4242) to verify they pass Luhn validation before using them in tests.