Methodology
This page explains how the site builds card-generation outputs, curates provider testing references, and estimates PSP fee comparisons.
Card generation methodology
Generated card numbers are synthetic and designed for testing or educational use. They follow valid checksum patterns such as the Luhn algorithm but are not tied to real bank accounts.
Test cards methodology
Provider-specific test card scenarios are curated from public documentation for Stripe, Adyen, Checkout.com, and Airwallex. Provider-specific fields like trigger amounts, response codes, AVS/CVC responses, and challenge behavior are preserved where relevant.
Fee comparison methodology
Fee estimates are derived from public pricing and documented assumptions around card brand, card type, merchant region, and issuer relationship. Results are directional and may differ from negotiated merchant contracts or interchange-plus agreements.
Update model
Pages are updated when provider documentation changes, implementation issues are discovered, or users report stale references. Public sources are preferred over unsupported assumptions whenever possible.