Credit card validator

Check whether a card number is correctly formed and which network it belongs to. The check runs in your browser, and nothing you type is sent or stored.

Card number

Check number

Test card numbers

Standard numbers published for testing payment forms. They pass the check but are not real cards and cannot be charged.

Card number ranges by network

Questions

Does a valid result mean the card is real?

No. It means the number is correctly formed: the right length for its network and a check digit that adds up. It cannot tell whether the card was ever issued, is still active or has funds. Only the card issuer can confirm that, when a payment is made.

Is it safe to enter a card number here?

The check runs entirely in your browser and nothing is sent or stored. Even so, you never need to enter a real card to test this tool: use one of the test numbers on this page.

How does the check work?

Card numbers end in a check digit worked out with the Luhn formula (ISO/IEC 7812). Every second digit from the right is doubled, the digits are added up, and the total must divide by 10. Any single mistyped digit breaks it.

How can I tell which network a card belongs to?

From the first digits, called the IIN or BIN. Visa numbers start with 4, Mastercard with 51–55 or 2221–2720, and American Express with 34 or 37. The table on this page lists the main ranges.

What are test card numbers?

Numbers published for developers to test payment forms. They pass the Luhn check but are not real cards and cannot be charged. They only work in a payment provider's test mode.

Why is my number valid but showing a length warning?

Each network uses fixed lengths. For example, American Express cards always have 15 digits. A number with a correct check digit but the wrong length for its network has probably been copied wrongly.