Credit card BIN / IIN checker
The first 6-8 digits of any payment card are the Bank Identification Number — a public prefix that maps to a card network. This checker matches the prefix against known ranges for Visa, Mastercard, American Express, Discover, JCB, Diners Club, UnionPay and Maestro, and runs a Luhn check when a full number is supplied.
You only ever need the BIN, not a full card number, and everything runs in your browser with nothing uploaded.