Hey Product Hunt 👋 Built Luhnly after noticing most "credit card generator" tools online are either cluttered with ads, feel sketchy to use, or don't make it obvious who built them or why. Wanted something that just does the one thing well: generates Luhn-valid test numbers, explains the math, and gets out of your way. A few things worth knowing: Every number is genuinely Luhn-valid — actually found and fixed a bug in my own checksum logic before launch, which felt important to mention given correctness is the entire point of the tool Runs 100% in your browser, nothing stored or tracked beyond basic analytics Free guides for Stripe, PayPal, Square, Braintree, and Authorize.net sandbox testing, since they all behave differently in ways that aren't obvious the first time (PayPal accepts any Luhn-valid number; the other four require their own specific reserved cards — that tripped me up before I built this) Would love feedback, especially from anyone who tests payment integrations regularly — what's missing, what's annoying, what you'd want next.

Luhnly

Fake credit card numbers that actually pass validation

Fake credit card numbers that actually pass validation