Credit Card / Luhn Validator

Validate any credit card number with the Luhn (mod-10) checksum, detect the issuing brand (Visa, Mastercard, Amex, Discover, Diners, JCB, UnionPay), and check format. Browser-only — your card number is not transmitted.

How to use the Credit Card / Luhn Validator

Type or paste a card number; spaces and dashes are stripped. Validation runs as you type. Don't use this with a real production card on shared computers. For testing, use known test numbers (Stripe publishes a full list).

About the Luhn algorithm

The Luhn algorithm is a simple checksum that catches most single-digit errors and transpositions. It's used by every major card brand, plus IMEI numbers, Canadian SIN, US NPI, and others. It's not a fraud check — knowing the algorithm doesn't validate that a card exists or is funded. It only confirms the digits could be a real number.

Frequently asked questions

Does a valid Luhn check mean the card is real?
No. Luhn only confirms the digits form a well-structured number that passes the checksum. It says nothing about whether the card exists, is active or has funds.

Is it safe to enter a card number here?
The check runs entirely in your browser and nothing is transmitted, but as a habit do not enter real card numbers into web tools. Use published test numbers instead.

What else uses the Luhn algorithm?
Beyond payment cards, Luhn validates IMEI device numbers, Canadian SINs, US National Provider Identifiers and several other identifier schemes.
Embed this tool on your site

Free to embed, no attribution required (but appreciated). Paste this where you want the tool to appear: