How to validate a credit card number
Enter one card number candidate or paste a list. The validator removes spaces and hyphens, checks the remaining characters and digit count, tests the Luhn checksum, and reports a matching network prefix when it finds one. Results show the last four digits for longer values and explain failed checks.
How to use the Credit Card Validator
- Select Single Candidate for one value or Bulk Candidates for a list.
- Enter one value in Card number candidate, or paste values into Card number candidates.
- Separate bulk values with line breaks, commas, or both; empty entries are ignored.
- Read the status, network, digit count, and reasons in the result.
- In bulk mode, select Copy CSV or Download CSV to reuse the result table.
What the validation status checks
A Valid format result requires digits after spaces and hyphens are removed, a total of 12 to 19 digits, and a passing Luhn checksum. Network detection adds a name when a built-in prefix matches. A network-length mismatch appears as a reason, while the network check does not decide the status.
Input: 4111 1111 1111 1111
Masked number: **** **** **** 1111
Status: Valid format
Network: Visa
Luhn checksum: PassesThe single result lists Masked number, Digit count, Allowed characters (digits/spaces/hyphens only), Length in 12-19 digit range, Detected network, Length matches detected network, and Luhn checksum. Bulk results show Masked Number, Network, Digits, Status, and Reasons.
What happens to spaces and other characters
The validator trims the candidate, then removes spaces and hyphens. Letters, punctuation, and any other remaining characters fail the allowed-character check. Empty input is reported as Empty input. A digit count below 12 or above 19 fails the length check.
Input: 5500-0000-0000-0004
Normalized digits: 5500000000000004
Network: Mastercard
Status: Valid formatUnknownmeans the candidate has no matching built-in network prefix. Length and Luhn checks still run.- Numbers longer than four digits show their last four digits. Four or fewer digits are fully masked.
- Input containing invalid characters has no masked result. The validator stops before the length, network, and Luhn checks.
How to copy bulk credit card validation results
Bulk CSV output includes Masked Number, Network, Digit Count, Length OK, Luhn OK, Status, and Reasons. The number field contains the masked value, so the CSV does not include the full candidate. Copy CSV places the text on the clipboard when copying is available; Download CSV creates credit-card-validation-results.csv.
How network labels affect the result
The validator checks built-in prefixes for Visa, Mastercard, American Express, Discover, Diners Club, JCB, UnionPay, and Maestro. The list is informational and does not cover every possible prefix. A candidate can show Unknown and still pass the length and Luhn checks, because the network label is separate from the Valid format status.
For a group of values, paste the column into Card number candidates. The table keeps one row per non-empty entry and shows its masked number, network, digit count, status, and reasons. Use the reasons to distinguish an invalid character, an out-of-range length, or a failed checksum.
Choose the right data validation tool
Use Data Validation Tools to choose a validator for another data type. The IBAN Validator checks an IBAN's country prefix, expected length, BBAN structure, and MOD-97 checksum. The Email Validator checks email syntax, domain, quoting, length, and character rules. The Phone Number Validator & Formatter checks country, number type, validity, and available formatting results.
Frequently asked questions
What does a valid format credit card result mean?
A valid format result means the candidate passed the allowed-character, 12 to 19 digit, and Luhn checks. It does not verify issuance, activity, funding, ownership, or payment authorization.
Can I validate multiple credit card numbers at once?
Yes. Select Bulk Candidates and paste one candidate per line, comma-separated values, or a mixture of both.
Does the credit card validator check if a card is active?
No. It performs structural checks in the browser and does not contact a card network, issuer, or payment processor. The candidate stays in the page while the checks run.
How are spaces and hyphens handled in a card number?
Spaces and hyphens are removed before the digit, length, network, and Luhn checks run. Other remaining characters cause the allowed-character check to fail.