Credit Card Number Generator
Credit card numbers follow specific formats defined by each payment network. The last digit is a check digit calculated using the Luhn algorithm (also known as the mod-10 algorithm), which validates the number's integrity. Each brand has designated BIN (Bank Identification Number) prefixes that identify the issuing network.
This tool generates valid test credit card numbers with correct Luhn check digits for software testing and development. The numbers follow real brand prefix patterns but are not connected to any actual bank accounts. All generation is performed locally in your browser.
How it works
The Luhn algorithm doubles every second digit from right to left, subtracts 9 from results over 9, sums all digits, and the check digit makes the total a multiple of 10. BIN prefixes: Visa (4xxx), Mastercard (51-55xx), Amex (34/37xx), Discover (6011/644-649/65xx), Elo (636368/438935/etc), Hipercard (606282).
Use cases
- Testing payment form validation and formatting
- Populating test databases with realistic card data
- Verifying Luhn check digit implementations
- QA testing of checkout and payment flows
Frequently asked questions
Do generated credit card numbers work for real purchases?
No. The generated numbers only pass format and Luhn check-digit validation — they are not linked to any bank account, cardholder, or credit line. Any real payment attempt is declined at the issuer authorization step. They exist solely for testing payment forms and software.
What is the Luhn algorithm?
The Luhn (mod-10) algorithm validates card numbers: starting from the right, every second digit is doubled, 9 is subtracted from any result over 9, all digits are summed, and the number is valid if the total is a multiple of 10. The final digit of every card number is a check digit chosen to satisfy this rule. It catches typos like single-digit errors and most adjacent transpositions.
How do I identify a card brand by its number?
The BIN (Bank Identification Number) prefix at the start of the number identifies the network: Visa starts with 4, Mastercard with 51–55, American Express with 34 or 37, Discover with 6011, 644–649, or 65, and Hipercard with 606282. Card length also varies — Amex uses 15 digits while most other brands use 16.
What are test card numbers used for?
Developers and QA teams use them to test payment form validation, number formatting and masking, brand detection, and Luhn check implementations without touching real card data. They are also useful for populating test databases with realistic-looking records. Payment gateways additionally publish their own official test numbers for sandbox transactions.
Is it legal to generate credit card numbers?
Generating Luhn-valid numbers for software testing is legal and standard industry practice — the numbers are mathematical constructs not tied to any account. What is illegal is attempting to use any number, generated or not, for fraudulent transactions or trying to guess real active cards. This tool generates everything locally in your browser and is intended for development use only.