웹 개발
Credit Card Validator
Luhn 알고리즘으로 카드 번호를 검증하고 결제 네트워크와 자릿수를 확인합니다. 모든 계산은 브라우저에서 이루어지며, 번호는 어디로도 전송되지 않습니다.
자주 묻는 질문
Does a passing check mean the card is real and has funds?
No — this tool only verifies the Luhn checksum and the expected digit length for the detected network; it can't tell you whether the card actually exists, is active, or has funds, since that requires contacting the card issuer.
How does the Luhn algorithm work?
It doubles every second digit from the right, sums the digits of the results together with the untouched digits, and checks that the total is a multiple of 10 — it catches most typos and transposed digits but isn't a fraud check.
Is my card number sent anywhere?
No, validation happens entirely in your browser and the number is never transmitted or stored.