Credit Card Validator
Check any card number with the Luhn algorithm, detect the card network, and generate valid test numbers — free, private, no upload required.
Credit Card Validator checks any card number against the Luhn checksum algorithm, detects the card network (Visa, Mastercard, American Express, Discover, Diners Club, JCB, UnionPay, Maestro), and can generate Luhn-valid test numbers for checkout-flow testing. Everything runs locally in your browser — nothing is ever sent to a server. Built by FreeToolHub.
Generate a test number
Generated numbers only satisfy the Luhn checksum and network prefix rules. They are not linked to any real account and cannot be used to make a real purchase — for testing checkout forms and validation logic only.
Frequently Asked Questions
What is the Luhn algorithm?
The Luhn algorithm (also called mod 10) is a simple checksum formula used to validate a range of identification numbers, including credit and debit card numbers. It doubles every second digit from the right, subtracts 9 from any result over 9, and checks that the total sum is a multiple of 10.
Is it safe to test my real card number here?
Yes. Everything runs locally in your browser using JavaScript. Your card number is never sent to any server, stored, or logged. That said, this tool only checks the Luhn checksum and card format — it cannot tell you whether a real card is active, has funds, or is genuinely issued.
Which card networks does this tool detect?
It recognizes Visa, Mastercard, American Express, Discover, Diners Club, JCB, UnionPay, and Maestro based on their published number ranges (IIN/BIN prefixes) and expected lengths.
Can I use the generated test numbers to make a real purchase?
No. Generated numbers only satisfy the Luhn checksum and network prefix rules — they are not linked to any real account, have no funds behind them, and will be declined by any real payment processor. They are meant purely for testing checkout forms and validation logic.
Why does a real-looking number show as invalid?
A number can look plausible but still fail the Luhn checksum, have the wrong number of digits for its network, or use a prefix that isn't assigned to any known network. Any of these will cause this tool to mark it invalid.