How cashier-less stores and carts in Amazon, Whole Foods, and Kroger work, helping shoppers skip the checkout line

• Major retailers are experimenting with cashier-less store experiences.
• These computer vision-powered shopping experiences have been in development for years.

Retail giants have increasingly leveraged in-store technology that allows customers to buy products without waiting in line for the cashier. By marrying advancements in artificial intelligence and computer vision, cameras and sensors, and deep learning algorithms, these locations permit visitors to shop by simply picking up goods or placing products in their carts, nixing the need for a cash register altogether.

The trend appears to be catching on across the retail industry. Kroger and Albertsons have partnered with smart cart startup Veeve for a pilot that has rolled out in select stores. Amazon Go stores began opening to the public in 2018. Amazon's grocery acquisition Whole Foods Market just launched its first store in DC which uses its parent company's "Just Walk Out" technology. And while the actual number of stores offering cashier-less experiences in the United States remains small, major retailers' embrace of this technology is an indication that the technology is here to stay.

Part of the reason behind the slow introduction of cashier-less experiences is the fact that the technology is expensive and complicated. These stores depend on a network of artificial intelligence-powered cameras and weight sensors, installed either in the store's ceiling, shelves, or shopping carts.

These systems can track the location of different items — noting when a customer removes or replaces products from shelves. They also register prices, tallying a customer's basket and sending out receipts at the end of a shopping trip.

Amazon has long touted computer vision technology as a method for achieving "a checkout-free or cashier-less checkout experience."

"While they haven't revealed too much about their technological advancement, it appears that Amazon plans on making cameras central to their operational strategy," Alex Polacco, a professor of management St. Cloud State University, and MBA graduate Kayla Backes, wrote in a 2017 article published in the Journal of Business and Management.

But the technology behind the company's Just Walk Out service, Dash Carts, and Amazon Go locations has gone through numerous iterations before hitting stores.

In the 2021 book "Amazon Unbound: Jeff Bezos and the Invention of a Global Empire," journalist Brad Stone reported that the team behind Amazon Go was struggling at the start of 2016 after an "ill-fated demo" failed to impress then CEO Jeff Bezos and his S-team.

Bezos had once "envisioned thousands of Amazon Go stores, in urban areas around the country." Instead, Amazon Go got off to a slower start than its founder initially anticipated, kicking off with a handful of stores.

Stone wrote that Amazon has had success with licensing its Just Walk Out service to a number of other retailers. Now, Whole Foods Market has been added to that roster. The grocery chain has described this technology as incorporating "a combination of computer vision, sensor fusion, and deep learning"—similar to what you'd find in self-driving cars."

But Amazon and Whole Foods aren't the only game in town when it comes to cashier-less technology. Other retailers have embraced startup technology that doesn't require adding overhead cameras.

Instacart recently acquired smart-cart manufacturer Caper. Amazon alumni Shariq Siddiqui and Umer Sadiq also founded a smart cart startup called Veeve. The company took off during the pandemic, partnering with big name clients like Kroger and Albertsons.

While Amazon's Just Walk Out services features cameras and sensors plugged into the store's ceilings and shelves, Caper and Veeve store their barcode scanners and cameras within their speciality shopping carts.

But while the cashier-less technology has taken multiple forms, the principal remains the same.

"What we're really doing is watching the customer shop," Siddiqui previously told Insider.