Credit card validator
Validate a card number with the Luhn algorithm and detect the network.
Use test numbers. Validation is local; do not enter a real card.
🔒 100% client-side — no data sent
Validate a credit card number with the Luhn algorithm and detect the card network (Visa, Mastercard, American Express, Discover…). Perfect for testing dummy numbers during development or checking user input. 100% browser-side processing, so no number is ever sent or stored.
What is it for?
- ▸ Test dummy card numbers during payment development.
- ▸ Check a number's validity with the Luhn algorithm.
- ▸ Identify the network (Visa, Mastercard, Amex) from the leading digits.
- ▸ Validate a card entry before calling a payment gateway.
FAQ
What is the Luhn algorithm?
It's a checksum formula that detects typos in a card number. It doesn't prove the card exists, only that the number is internally consistent.
How do you recognize a card's network?
By the leading digits (IIN/BIN): 4 for Visa, 51-55 and 2221-2720 for Mastercard, 34/37 for American Express, 6011/65 for Discover.
Can I enter a real card number safely?
Validation is local and nothing is transmitted. As a rule, still prefer test numbers and never enter real banking data into an online tool.
Is a Luhn-valid number usable?
No. Luhn only checks mathematical consistency. A real card needs an active account, a valid expiry date and CVV verified by the bank.