The Luhn algorithm is a simple checksum used to catch typos in identification numbers — most famously credit card numbers. This tool checks whether a number passes the Luhn check and detects the likely card type, entirely in your browser. It validates the format only; it does not check whether an account exists.
How to use it
- Type or paste the number.
- The tool reports whether it passes the Luhn checksum.
- For card-length numbers, the likely card type is shown.
About Luhn / Card Validator
The Luhn algorithm is a deliberately simple formula that detects single-digit errors and most transpositions — exactly the mistakes people make when typing a long number. It is used for credit cards, IMEI numbers and various account identifiers. This validator runs the Luhn check and, for card-length inputs, identifies the brand from its number pattern. It is useful for client-side form validation and for understanding how the check works. Validation is entirely local: nothing is sent anywhere, and a passing result only means the number is well-formed, not that it belongs to a real account.
FAQ
Does passing Luhn mean the card is real?
No. It only means the number is correctly formed and free of typos. It says nothing about whether an account exists or has funds.
What is the Luhn algorithm used for?
Catching typos in numbers like credit cards and IMEIs. It is a checksum, not a security measure.
Is my input sent anywhere?
No. The check runs entirely in your browser.