Validation results will appear as you type
What is the Luhn Algorithm?
The Luhn algorithm, also known as the "modulus 10" algorithm, is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers, IMEI numbers, and Canadian Social Insurance Numbers. It was created by IBM scientist Hans Peter Luhn and is described in U.S. Patent No. 2,903,645.
Note: This tool checks structural validity only. It does not verify the available balance, expiry date, or if the account is currently active.
How It Works
- 1. From the rightmost digit, double the value of every second digit.
- 2. If doubling a digit results in a number greater than 9, subtract 9 from the product.
- 3. Sum all the resulting digits.
- 4. If the total modulo 10 equals 0, the number is valid.
Privacy-First Architecture
Security is our priority. This application uses volatile memory only. We do not use cookies, local storage, or external server pings. When you refresh or close this tab, all session data is permanently erased.