Credit Card Validator
Validate credit card numbers using the Luhn algorithm. Identifies the card brand and verifies the check digit, no data sent to servers.
How does the Luhn algorithm work?
The Luhn algorithm (or modulo 10) is used by all credit card brands. From the right, every second digit is doubled — if the result is greater than 9, subtract 9. The sum of all digits must be divisible by 10.
The brand is identified by the first digit: Visa starts with 4, MasterCard with 5, Elo with 6.
The check runs entirely in your browser. No number entered is sent to servers.
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