All major browser makers are implementing a new World Wide Web Consortium (W3C) Payment Request API standard, which means faster, more secure web checkouts are right around the corner as early as mid-2018. When implemented, the Payment Request API standard is particularly important for mobile web, where retailers see average conversion rates at one-third of desktop conversion rates. The new standard enables developers to create a streamlined checkout page where users can reuse stored payment and address information, making checkout faster and reducing typing errors.
How does the consumer experience work?
1) The user registers different payment methods she’d like to use in her browser such as card payments, third-party digital payments, bitcoin or debit transfers.
2) During the checkout experience, the browser determines which methods the merchant offers that match the user’s preferences and displays only the methods preferred by that user.
3) The merchant can also request the user’s shipping address. The browser then presents this stored information on the billing page.
4) The user than chooses the payment method, after which the browser transmits the user’s payment information to the merchant for processing.
Stripe’s Demo of Payment Request API :
How is it better than autofill or autocomplete?
Autocomplete was designed to address mainly credit card scenarios (and thus only works with form fields). Autocomplete is not operable with systems like Apple Pay and Android Pay, nor was it designed for integration into third-party software such as financial system on- boarding.
Where can my developers learn more?
Beyond user experience improvements, the new standard promises easier deployment for checkout page developers and integration of new payment methods.
The Web Payments Working Group published documentation that provides more detail. To learn more visit: W3C’s press release and the Payments Request FAQ on GitHub.
 Source: W3C Payment Request API FAQ page, GitHub (https://github.com/w3c/payment-request-info/wiki/FAQ#deployment-and-status-questions).