Amazon's Prime subscribers can order items for one-or two-hour delivery on their web browsers provided the service covered their zip code, following the launch of a dedicated site for its Prime Now same-day delivery service.
Earlier Prime subscribers had to use Amazon's mobile app to place their orders.
Two-hour delivery is offered at no cost, while one-hour would cost $7.99, on several items including cleaning products, perishables, and Amazon's own hardware.
The service also extended to takeout food from certain restaurants, and goods from local stores including Sprouts Farmers Market and Sprinkles in Chicago, Los Angeles, Manhattan, Portland, San Diego, and Seattle.
"We have expanded the service rapidly over the last year to new cities and customers told us that they would want the option to shop on a browser as well as mobile," Stephenie Landry, head of Amazon's Prime Now service, said in a statement.
Bloomberg first reported last month that the company would bring Prime Now to the web, indicating that it would be an option on Amazon.com, rather than a dedicated site.
According to commentators, as Prime Now continued to expand, it seemed like the rapid delivery service would play a key role in Amazon's future plans.
The delivery option is currently not available on Amazon's main shopping site, and product selection is limited to tens of thousands of items. The web launch, however, pointed to the service as being a key piece of Amazon's future.
The Prime Now service specialised in selling health, beauty and household items, and also fresh and packaged groceries. Amazon had partnered with local grocers in certain markets, but also competed against them by selling the same products itself in certain cases.