Test Card Validator (Luhn)
Check a test card number with the Luhn algorithm and identify its brand — free, fast and private.
Only use test/sandbox card numbers from a payment provider's own test documentation. Never enter a real card number here.
Validator only — it never generates card numbers. A passing Luhn check only means the digits are well-formed; it does not mean the card is real, active, or has money on it. Test cards must only be used in sandbox/test environments, never for a real payment.
How to use Test Card Validator (Luhn)
- Paste a test card number from a payment provider's sandbox/test documentation — never a real card number.
- Press Validate Card Number. The tool strips spaces and dashes and runs the Luhn checksum.
- Read the result: the brand identified from the number's prefix, the length check, and whether the Luhn check passed.
- Use Copy Result to save the verdict, or Clear to check another number.
Validator only — it never generates card numbers. It only checks whether digits are well-formed (Luhn + brand prefix). Test cards must only be used in sandbox/test environments, never for a real payment.
Frequently Asked Questions
What is the Luhn check?
The Luhn algorithm is a simple checksum used by card networks: it catches typos and mistyped digits. A number that fails Luhn was never a valid card number.
Does a passing check mean the card is real?
No. Luhn only proves the digits are well-formed. It says nothing about whether the card exists, is active, or has funds.
Which card brands are recognised?
Visa, Mastercard, American Express, Discover, JCB and UnionPay are identified from the number's starting digits. Other prefixes are reported as an unknown brand.
Can I use a test card for a real payment?
No. Test cards only work in a payment provider's sandbox/test mode. Using one for a real purchase will fail, and entering real card details into any random website is unsafe.