Credit Card Regex Javascript Validator

What is Credit Card Regex in JavaScript?

In JavaScript, a credit card regex is a regular expression used to verify whether an input string matches the format of a valid credit card number. These patterns help filter out incorrectly formatted numbers before backend validation or payment processing. They are especially useful for front-end form validation and protecting against invalid user inputs.

A good credit card regex validator can check numbers entered either in 4-digit groups (like or ) or as a continuous string of digits (). This flexibility ensures users can input their card details in whichever way is most convenient, while still maintaining strong validation standards.

JavaScript-based credit card regex patterns are ideal for:

• Ensuring input format accuracy in forms before submission

• Instant client-side validation for smoother user experience

• Preventing non-numeric or improperly structured entries

With these patterns, you can quickly screen for valid credit card formats and provide immediate feedback to users, streamlining the checkout process and minimizing errors before any sensitive data reaches your server.

Common Regex Patterns for Credit Cards

Credit card formats vary by provider. Below are common regex patterns used for each type:

// Visa (starts with 4, 13 or 16 digits)
^4[0-9]{12}(?:[0-9]{3})?$

Example: 4111111111111111

// MasterCard (starts with 51–55 or 2221–2720, 16 digits)
^5[1-5][0-9]{14}$|^2(2[2-9][0-9]{2}|[3-6][0-9]{3}|7[01][0-9]{2}|720[0-9]{2})[0-9]{10}$

Example: 5500000000000004

// American Express (starts with 34 or 37, 15 digits)
^3[47][0-9]{13}$

Example: 340000000000009

// Discover (starts with 6011 or 65, 16 digits)
^6(?:011|5[0-9]{2})[0-9]{12}$

Example: 6011000000000004

How to Validate Credit Card Numbers Using Regex in JavaScript

Here’s a complete working code example to validate a Visa card number using regex:

function isValidCreditCard(cardNumber) {
  const cardRegex = /^4[0-9]{12}(?:[0-9]{3})?$/; // Visa pattern
  return cardRegex.test(cardNumber);
}

// Example usage
const testCard = "4111111111111111";
console.log(`Is "${testCard}" valid?`, isValidCreditCard(testCard)); // true

Replace the regex pattern with MasterCard, Amex, or Discover to validate those types accordingly.

Flexible Input Formatting

You can enter your credit card number into the validator using either spaced groups (like 4111 1111 1111 1111) or a continuous string of digits (4111111111111111). The tool automatically recognizes and validates either format, making it easy to check your card regardless of how it's typed or copied.

Real-World Use Cases

• Online Checkout Forms: Validate card number formats before sending to payment gateway.

• Mobile Apps: Reduce API calls by validating credit card input locally.

• Data Cleaning: Use regex patterns to clean up scraped or imported card data.

Pro Tips

• Use Luhn’s Algorithm along with regex for stronger validation—regex checks format, but Luhn checks actual card validity.

• Avoid storing raw credit card numbers; always tokenize or encrypt them.

• Always use HTTPS when handling sensitive inputs like credit card data.

• Combine with our Password Regex JavaScript Validator to create secure user flows.

• Use the JavaScript Regex Tester to test your patterns on the fly.

• For UUIDs in your backend or token system, check UUID Regex JavaScript Validator.

Frequently Asked Question: Does This Validator Save My Card Numbers?

Rest assured—none of the credit card numbers you validate here are ever stored or logged anywhere. All validation happens instantly on your device, so your sensitive data stays private and secure. You can check your card formats with complete peace of mind!

Combine with These Tools

Make your validation stronger and more comprehensive by pairing this tool with:

• JavaScript Regex Tester: Test and debug your regex patterns interactively.

• Password Regex JavaScript Validator: Ensure your user authentication is strong from the frontend.

• Email Regex JavaScript Validator: Validate emails in tandem with card inputs during checkout.

• SSN Regex JavaScript Validator: Useful for forms requiring identity verification.

• Mac Address Regex JavaScript Validator: Helpful for IoT apps collecting user device data.