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Credit card regex tester

Test card number patterns for Visa, Mastercard (including the 2221-2720 2-series), American Express, Discover, JCB, Diners Club and UnionPay. Paste numbers one per line with or without spaces and dashes. Each line shows match or no match, the detected brand and a Luhn checksum result. Copy JavaScript, Python or an HTML pattern when you are ready.

Card number patterns by brand

Each pattern checks the issuer prefix and the digit count on a number with spaces and dashes removed (value.replace(/[\s-]/g, '')). Default pattern: ^(?:4\d{12}(?:\d{3})?|(?:5[1-5]\d{2}|222[1-9]|22[3-9]\d|2[3-6]\d{2}|27[01]\d|2720)\d{12}|3[47]\d{13}|6(?:011|5\d{2})\d{12}|3(?:0[0-5]|[68]\d)\d{11}|(?:2131|1800|35\d{3})\d{11})$. Every preset below is checked against its match and no-match samples, and every match sample passes the Luhn check.

Regex plus the Luhn checksum

function luhn(digits) {
  let sum = 0;
  let double = false;
  for (let i = digits.length - 1; i >= 0; i--) {
    let d = Number(digits[i]);
    if (double) { d *= 2; if (d > 9) d -= 9; }
    sum += d;
    double = !double;
  }
  return sum % 10 === 0;
}

const CARD_RE = /^(?:4\d{12}(?:\d{3})?|(?:5[1-5]\d{2}|222[1-9]|22[3-9]\d|2[3-6]\d{2}|27[01]\d|2720)\d{12}|3[47]\d{13}|6(?:011|5\d{2})\d{12}|3(?:0[0-5]|[68]\d)\d{11}|(?:2131|1800|35\d{3})\d{11})$/;
const digits = value.replace(/[\s-]/g, "");
const ok = CARD_RE.test(digits) && luhn(digits);

Strip separators, test the brand pattern, then run the Luhn check: from the right, double every second digit, subtract 9 from any result over 9, and add everything up. A valid number gives a total divisible by 10. 4111 1111 1111 1111 passes; 4111 1111 1111 1112 matches the Visa regex but fails Luhn. On a text input, the pattern attribute can enforce the digit format, and inputmode="numeric" with autocomplete="cc-number" gives a number keypad and autofill.

Do not collect card numbers in your own forms

Never store or send real card numbers through a contact form, email or database. That puts you in PCI DSS scope. Use a payment provider's hosted field or checkout so card data goes straight to the provider. Use these patterns for test data, for masking numbers that people paste into the wrong field, or for checks inside a provider's own form. For other form fields, try the phone regex tester.

Credit card regex FAQ