How it works
Enter Number
Type your credit card number. The tool will automatically format it with spaces for easier reading.
Network Detection
We instantly identify the card network (Visa, Mastercard, Amex, etc.) based on the starting digits.
Luhn Validation
The Luhn algorithm (Mod 10) runs in real-time to check if the card number follows the mathematical checksum rules.
Privacy First Validation
Validating card numbers can be sensitive. That's why our validator works entirely inside your browser. No data ever leaves your device, and we never store or track the numbers you enter.
What is the Luhn Algorithm?
The Luhn algorithm, also known as the "modulus 10" or "mod 10" algorithm, is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers and IMEI numbers.
It was designed to protect against accidental errors, such as typing a digit incorrectly. It is not a security measure and cannot detect intentional fraud or verify if a card is actually active or has funds.