What is Payment Request?
Payment Request is a new way for merchants to accept payments online. It is integrated in most major browsers, and greatly simplifies the checkout experience for users.
1 Minute Summary
The Payment Request API is a new W3C web standard being introduced to make payments easier on a merchant website. It replaces the traditional billing address, shipping address and credit card forms with a browser dialog to efficiently get data from the user to the merchant.
Payment Request API is being implemented by most major browsers (Chrome, Edge, Firefox, Opera, and others).
Try it yourself
This site also has a demo that allows you to play with the various options available to the API.