Can these generated test cards process live money transactions?

NO. These numbers are purely synthetic test fixtures formatted to satisfy the mathematical Luhn algorithm (Mod 10) checksum and Major Industry Identifier (MII) prefixes. They are NOT linked to any bank account, line of credit, or financial institution and will be immediately declined if submitted to a live production payment gateway.

What is the Luhn algorithm (Mod 10)?

The Luhn algorithm, also known as the "modulus 10" formula, is a mathematical checksum formula created by IBM scientist Hans Peter Luhn in 1954. It is used by credit card issuers (ISO/IEC 7812) to validate that a card number was typed without accidental typos or transposed digits before contacting a bank.

How do I test successful vs failed payments?

When testing in sandbox environments (like Stripe Test Mode, Braintree Sandbox, or PayPal Sandbox), payment gateways provide specific documented test numbers (e.g., Stripe 4242 4242...) to trigger specific outcomes (success, insufficient funds, expired card). Use AddrGen's generator to test input masks, card brand detection algorithms, and Luhn checksum validation in frontend code.

Which card brands are supported for testing?

The generator produces test numbers formatted for Visa (16 digits starting with 4), Mastercard (16 digits starting with 51-55 or 22-27), American Express (15 digits starting with 34 or 37), and Discover (16 digits starting with 6011).

Luhn Checksum (Mod 10) Verification

QA Test Card Generator (Luhn Validated)

Generate format-accurate, Luhn-valid test card numbers, expiry dates, and CVVs for developer checkout staging, input masking tests, and payment form validation.

Strict Sandbox Notice: Generated numbers are algorithmically calculated test fixtures for software QA and input validation only. They hold no monetary value and cannot be used for fraudulent or real-world transactions.

Country:

Target State / Region

City / Locality Lock

Identity Gender

Deterministic CSPRNG

How the Luhn Algorithm (Mod 10) Works

Understanding the mathematical checksum verified by payment gateways:

1Double Every Second Digit

Starting from the rightmost check digit and moving left, double the value of every second digit.

2Sum the Product Digits

If doubling a digit results in greater than 9 (e.g., 7 × 2 = 14), sum the digits of the product (1 + 4 = 5).

3Modulo 10 Divisibility

Add all digits together. If the total modulo 10 equals 0 (e.g., 60 % 10 == 0), the card number is mathematically valid.

Frequently Asked Questions

Answers to common questions about test cards, sandbox credentials, and checkout testing.