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Credit Card Validator🔒 100% local
Validate credit card numbers using the Luhn algorithm. Identifies card type (Visa, Mastercard, Amex, etc.).
Related Tools
Runs the Luhn checksum over a card number and works out the network from its leading digits. Spaces are stripped out, the digits are walked from the right with every second one doubled and reduced by nine, and the page reports the detected type, whether the checksum passes, and how many digits the number holds. The number is read and checked in the tab, and it is neither stored nor sent to a server.
How to use it
- Paste the number, with or without the spaces printed on the card.
- Press Validate.
- Read the type, the Luhn result and the digit count.
Worked example
4242 4242 4242 4242becomesCard Type: Visa
Luhn Check: VALID ✓
Length: 16 digits
This card number passes the Luhn algorithm check.The standard Visa test number. It passes the checksum and belongs to no account.
4111 1111 1111 1112becomesCard Type: Visa
Luhn Check: INVALID ✗
Length: 16 digits
This card number fails the Luhn algorithm check.One digit differs from a valid test number, so the checksum fails even though the prefix is still a Visa range.
When to use it
- You are testing a checkout form and need numbers that pass and numbers that fail.
- A payment page rejected a number and you want to know whether it is simply mistyped.
- You need the network behind a number when the card is not in front of you.
What it does not do
- Passing Luhn means the digits are internally consistent, nothing more. It does not say the card exists, is active, or has any funds.
- The network is inferred from a prefix list where the first match wins, so a number outside the classic ranges can come back as Unknown or as the wrong brand.
- Security codes and expiry dates are not checked and there is no issuer lookup, so this is a form-level check rather than a substitute for a payment processor.