Validates or generates numbers using the Luhn algorithm (Modulus 10). Used to verify credit card numbers, IMEI numbers, and other identification numbers. Detects single-digit errors and most transposition errors.
Inputs
Input: The number to validate (digits only).
Generate Length: Length of the random number to generate (12-19 digits).
Tips
The last digit of a card number is the Luhn check digit.
Luhn detects all single-digit errors and most adjacent transposition errors.
This is NOT a security mechanism — it's only for error detection.
Step-by-step display shows the Luhn calculation for learning.