About this tool
Validate a number with the Luhn check digit algorithm and guess the card brand, entirely in your browser.
Frequently asked questions
Does a valid result mean a real card?
No. The Luhn check only confirms the digits form a valid checksum; it does not mean the account exists or is active.
Which brands are detected?
Visa, Mastercard, American Express and Discover, recognised by their number prefixes and lengths.