Credit Card Validator

Quickly and easily validate your Credit Card! Our Credit Card validator ensures the authenticity of the provided number, confirming that it is valid and error-free. If you need to generate a new Credit Card number, try our Credit Card generator.

This tool generates fictitious data intended exclusively for software testing and development purposes. The data does not correspond to real people or entities and must not be used for illegal, fraudulent purposes, or in ways that violate the privacy of others. Compliant with LGPD (Brazilian Data Protection Law).

See also:

Unit Converter
RENAVAM Validator
CI (Uruguay)
Multi-Tool
State Registration Generator
CPF Generator
PIS/PASEP Validator
Certificate Generator

How Credit Card Validation (Luhn) Works

What does the validator check?

The Help4Dev credit card validator applies the Luhn algorithm (modulus 10) to verify whether a number is mathematically valid. It also identifies the card brand by prefix (BIN/IIN): Visa starts with 4, Mastercard with 51-55, American Express with 34 or 37, Elo with specific prefixes, Hipercard with 38 or 60, among others. Validation does not check balance, limit, or whether the card exists.

When is a card considered invalid?

A card is invalid when: (1) the number does not pass the Luhn algorithm; (2) the length does not match the brand standard (Visa has 16 digits, Amex has 15, etc.); (3) the prefix does not match any known brand. The validator reports both the Luhn verification result and the identified brand, facilitating analysis.

Why validate cards in development?

Payment gateways, e-commerce platforms, subscription systems, and any application accepting credit card payments need to implement Luhn validation before processing the transaction. Testing this validation requires valid and invalid numbers from various brands. The Help4Dev validator is an essential tool for quickly checking whether a Luhn implementation is correct.