Online Card Number Validator
Verify card numbers with the Luhn algorithm, detect card networks and formatting, all processed locally in your browser
FAQ
Luhn is the standard checksum for credit card numbers: double every second digit from the right (subtract 9 if over 9) and sum; valid if divisible by 10. It catches typos, not fraud.
Visa, Mastercard, American Express, Discover, JCB, Diners Club and UnionPay are detected by number prefix and length.
No. Passing only confirms the number format is valid. It cannot verify funds, ownership or usability - use it for development and input checking.
No. Everything runs locally in your browser; card data never leaves your device.
This tool only checks format, not real transactions. Public test numbers (e.g. 4111111111111111) work for all features - please avoid typing real card numbers in public.
Completely free. This is a pure frontend online tool - no registration required, no payment needed, just open and use.
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