Credit Card Number with Network Detection Regex for JavaScript

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching credit card number with network detection, ported and verified for JavaScript. Identity and credential patterns need both correctness and safety, since they're frequent targets for adversarial input. The snippet below is ready to drop into your JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// Credit Card Number with Network Detection
// ReDoS-safe | RegexVault — Identity & PII > Financial PII

const creditCardNumberWithNetworkDetectionRegex = /^(?:(4)[0-9]{12}(?:[0-9]{3,6})?|(5[1-5][0-9]{14}|2(?:2[2-9][1-9]|[3-6][0-9]{2}|7[01][0-9]|720)[0-9]{12})|(3[47][0-9]{13})|(3(?:0[0-5]|[68][0-9])[0-9]{11})|(6(?:011|5[0-9]{2})[0-9]{12,15})|((?:2131|1800|35[0-9]{3})[0-9]{11}))$/;

function validateCreditCardNumberWithNetworkDetection(input: string): boolean {
  return creditCardNumberWithNetworkDetectionRegex.test(input);
}

// Example
console.log(validateCreditCardNumberWithNetworkDetection("4111111111111111")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Identity & PII > Financial PII category and carries a ReDoS-safe certification. That matters for JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Capture groups: 1=Visa, 2=Mastercard, 3=Amex, 4=Diners Club, 5=Discover, 6=JCB. PCI-DSS: never store CVV, never log PANs, always encrypt stored card data, use tokenization for recurring billing.