Segurança

Credit Card Validator

Check whether a credit card number passes the Luhn checksum, detect the card brand (Visa, Mastercard, Amex, Discover, JCB, Diners, UnionPay, Maestro), and see the expected check digit for any partial number.

Resumo da ferramenta

Esta ferramenta aceita entrada estruturada e devolve saída determinística no navegador, sem upload para o servidor.

Nome da ferramenta: Credit Card Validator
Intenção da entrada: Forneça conteúdo de origem para transformar, validar ou analisar.
Intenção da saída: Receba uma saída normalizada pronta para copiar, reusar ou depurar.
Entrada de exemplo: 4111 1111 1111 1111
Saída de exemplo: Valid Visa test number (passes Luhn).

Card number

Valid Visa card number (passes Luhn check).

Digits16

BrandVisa

Formatted4111 1111 1111 1111

Expected check digit0

This tool runs entirely in your browser. Numbers are never sent anywhere.

About the Luhn algorithm

The Luhn algorithm (ISO/IEC 7812-1) is a checksum used by credit cards, IMEI numbers, and some national IDs. Passing the check means the number is internally consistent — it does not mean the card has been issued, is active, or has funds available.

Introdução à ferramenta

Visão geral da ferramenta

The Luhn algorithm is the same checksum used by banks, IMEI numbers, and some national IDs. Passing the check means the digits are internally consistent — it does not mean the card has been issued, is active, or has funds. This tool runs entirely in your browser so numbers never leave your device. Use it for test data, QA, and to build intuition about how card numbers are structured.

Casos de uso

Use Credit Card Validator when you need fast validate credit card numbers with the luhn algorithm, detect the card brand, and compute the expected check digit — 100% client-side.
Handle security workflows directly in the browser with no install required.
Support SEO long-tail intent by covering quick checks, troubleshooting, and one-off conversions.

Exemplos de entrada/saída

Intenção da entrada

4111 1111 1111 1111

Intenção da saída

Valid Visa test number (passes Luhn).

Intenção da entrada

5500 0000 0000 0004

Intenção da saída

Valid Mastercard test number (passes Luhn).

Perguntas frequentes

Does this check whether the card is real?+

No. It only verifies the structural checksum. Real validation requires a payment gateway.

What brand lookup is used?+

A static table of Issuer Identification Number (IIN) prefixes and valid lengths for Visa, Mastercard, Amex, Discover, JCB, Diners, UnionPay, and Maestro.

Is my card number sent anywhere?+

No. Everything runs entirely client-side. Still, avoid pasting real cards on any site.