What is the Luhn Algorithm (Mod 10)?

The Luhn algorithm, created by IBM scientist Hans Peter Luhn in 1954 and standardized in ISO/IEC 7812-1, is a simple checksum formula used to validate a variety of identification numbers, such as credit cards, IMEI numbers, and national insurance identifiers against accidental typing errors.

Does a valid Luhn check mean a credit card is active or has funds?

No. The Luhn algorithm only mathematically verifies that the card number was constructed properly according to numbering rules and has no transposed digits. It does not check if the account is open, active, or valid with a financial institution.

Is my card number safe when tested on this site?

Yes. NexTools is completely client-side. The mathematical verification runs in your local JavaScript runtime without sending any data over the internet or writing to any database. We also provide synthetic dummy test card numbers for safe software testing.

Credit Card Luhn Algorithm Validator & BIN Inspector

Validate card numbers with step-by-step ISO/IEC 7812 Luhn (Mod 10) calculation. Detect issuer network and generate test numbers.

Enter Card Number (Digits Only)

PCI DSS Safe: Evaluated strictly in-memory client-side. Zero network transmission.

Card Issuer / Network Visa

Length 16 Digits

IIN / BIN Prefix 453201

Step-by-Step Luhn (Mod 10) Calculation Breakdown

Starting from rightmost check digit and moving left, every second digit is multiplied by 2. If the product is $>9$, digits are summed ($product - 9$).

Digit	Multiplier	Product	Summed Value

Total Modulo Sum: 60 Verification: 60 mod 10 = 0 (VALID)

How the ISO/IEC 7812 Luhn Algorithm Operates

The Luhn algorithm (also called the Modulus 10 algorithm) is an error-detecting checksum routine. It is designed to catch 100% of single-digit typographical errors and nearly all accidental digit transposition errors (e.g. typing 12 instead of 21).

Major payment brands enforce the algorithm: Visa cards always begin with 4, Mastercard with 51-55 or 2221-2720, and American Express with 34 or 37.

Frequently Asked Questions

Can this tool be used to steal or charge credit cards?

No. This tool performs pure mathematical checksum checking. It does not possess payment processing connections, merchant IDs, or CVV/expiry validation, making financial transactions impossible.

What is an IIN / BIN number?

The Issuer Identification Number (IIN), historically known as Bank Identification Number (BIN), refers to the initial 6 to 8 digits of a payment card number, uniquely identifying the issuing financial institution.