Credit Card Number Regex Tester
Validate credit card numbers with regular expressions
^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13})$Regex Flags
No matches found
Pattern Explanation
^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13})$No explanation available
About Credit Card Regex Patterns
Credit card validation combines format checking with mathematical verification (Luhn algorithm). Regex handles the format: correct length, valid prefix for card type, and proper digit grouping. The Luhn check confirms the number is mathematically valid.
Our credit card regex tester helps you recognize card types and validate format before processing payments.
Why Validate Credit Cards?
Early card validation improves UX and reduces payment failures. Catching typos before submission saves users from failed transaction messages and potential holds on their accounts.
Card type detection (Visa starts 4, Mastercard 51-55 or 2221-2720, Amex 34/37) enables showing the appropriate card logo, building user confidence their input is recognized correctly.
Building the Pattern
Card-specific patterns:
Visa: ^4[0-9]{12}(?:[0-9]{3})?$ (13 or 16 digits, starts with 4) Mastercard: ^5[1-5][0-9]{14}$ (16 digits, starts with 51-55) Amex: ^3[47][0-9]{13}$ (15 digits, starts with 34 or 37)
A combined pattern matches any major card type. Always follow with Luhn validation.
Common Use Cases
- Checkout form validation
- Card type auto-detection
- Payment form UX enhancement
- Data format verification
Pro Tip
Never rely solely on regex—always use the Luhn algorithm. And of course, never store raw card numbers; use tokenization via your payment processor.
Other Regex Patterns
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