Credit Card Validator
Validate credit card numbers using the Luhn algorithm. Detect card type automatically. All processing happens in your browser — numbers are never transmitted.
Supported Card Types
This tool only checks number validity using the Luhn algorithm and prefix matching. It does not verify that a card exists or has funds. No data leaves your browser.
About Credit Card Validator
Credit Card Validator checks whether a credit card number passes the Luhn algorithm checksum — the standard validation used by all major card networks. It also automatically detects the card type (Visa, Mastercard, American Express, Discover, and others) from the card number prefix.
The Luhn algorithm is a simple checksum formula used to detect single-digit errors and transpositions in card numbers. It doesn't verify the card is real or has funds — only that the number is mathematically valid.
Useful for testing payment forms in development, validating user input before API calls, or understanding how card number validation works.
Features
- ✓Luhn algorithm validation
- ✓Automatic card type detection (Visa, MC, Amex, Discover)
- ✓Valid/invalid indicator
- ✓Accepts formatted (spaces/dashes) card numbers
- ✓No server — all validation in-browser
Common Use Cases
- →Testing credit card input validation in development
- →Validating card numbers before sending to a payment API
- →Learning how the Luhn checksum algorithm works
- →Generating valid test card numbers for QA