Credit Card Validator provides validation utilities for credit card data inputs. It is designed as a CommonJS module for use in Node.js, io.js, or the browser. It includes first class support for 'potential' validity so you can use it to present appropriate UI to your user as they type. A typical use case in a credit card form is to notify the user if the data they are entering is invalid. In a credit card field, entering “411” is not necessarily valid for submission, but it is still potentially valid. Conversely, if a user enters “41x” that value can no longer pass strict validation and you can provide a response immediately.