Credit Card Validator
Check whether a card number passes the Luhn checksum and see its card type.
How to use the Credit Card Validator
- Enter a card number.
- See whether it passes the Luhn check and which brand it matches.
- Use test numbers only — never a card you actually use.
About the Credit Card Validator
The Credit Card Validator checks whether a card number passes the Luhn checksum and identifies which brand its digits match, such as Visa, Mastercard, American Express, Discover, Diners Club or JCB. The Luhn algorithm is a simple mathematical formula that most card networks use as a first line of defence against typos and mistyped digits. Enter a number and the tool instantly tells you whether the checksum is valid and which brand the leading digits point to.
Be clear about what this means, because it matters. Passing the Luhn check and matching a brand pattern only proves the number is well-formed. It does not mean the card is real, active, or has any funds. There is no way for a checksum tool to know any of that, and this tool contacts no bank or network. It is built for developers testing payment forms and validation logic using the published test card numbers that gateways provide.
For that reason, never enter a card you actually use. Stick to official test numbers from your payment provider. Everything runs in your browser and nothing is sent anywhere, but the safest habit is still to keep real card details out of any tool. Building test fixtures? A UUID Generator pairs well for mock records.
Frequently asked questions
Does a valid result mean the card is real?
No. A valid result only means the number passes the Luhn checksum and matches a known brand pattern, so it is well-formed. It cannot tell you whether the card exists, is active, or has any available funds.
What is the Luhn check?
It is a simple arithmetic formula that card networks use to catch typos. It processes the digits in a set pattern and confirms the total meets a rule. Most valid card numbers pass it, but passing it does not make a number a real card.
Can I test with my own credit card?
Please do not. Use only the official test card numbers published by your payment gateway. Entering a real card you use is an unnecessary risk, even though this tool sends nothing anywhere.
Which card brands does it detect?
It detects Visa, Mastercard, American Express, Discover, Diners Club and JCB based on the leading digits of the number. The brand is inferred from published number ranges, not from any live lookup.
Is the number I enter sent to a server?
No. The check runs entirely in your browser using the Luhn formula and pattern matching. Nothing is uploaded. Even so, only ever enter published test numbers, never a card in real use.