Credit Card / Luhn Validator
Check whether a credit-card number passes the Luhn checksum and detect the brand. Test data only.
Quick answer: Check whether a credit-card number passes the Luhn checksum and detect the brand. Test data only.
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Frequently asked questions
- Does passing Luhn mean the card is real?
- No. Luhn is a typo-detection checksum, not authentication. A passing number is internally consistent but may not be issued, may be expired, or may have no funds. Real validation needs a payment processor.
- Should I paste real card numbers?
- We'd rather you didn't — even though everything runs in your browser and nothing is sent anywhere, treat live card numbers like passwords. Use the standard test numbers (4242 4242 4242 4242, etc.) for development.
- Which card brands are detected?
- Visa, Mastercard, American Express, Discover, Diners Club, JCB, UnionPay and Maestro from their IIN ranges. Brand detection is independent of Luhn; both are reported.
- Is the data uploaded?
- No — every check runs in your browser using a few lines of JavaScript. Verify by opening DevTools → Network.
- Can I generate test card numbers?
- We don't generate them, but Stripe, Adyen and every other payment processor publishes their canonical test numbers for free.