Walmart is deploying millions of ambient Internet of Things battery-free sensors throughout its massive supply chain in the U.S.

The retail giant is using technology from Wiliot in what the IoT vendor is calling the first large-scale deployment of ambient IoT in the retail sector and one of the largest such implementations to date.

Ambient IoT is a class of IoT devices mainly powered by harvesting ambient energy from radio waves, light, motion, heat, or other viable ambient energy sources. It’s an evolution of legacy IoT and radio frequency identification technologies that promise lower costs and high scalability.

Walmart will be using the IoT sensors to track pallets nationwide by the end of 2026. “Expansion to other global markets is under consideration, but the immediate focus is the U.S. rollout,” Cathey said.

The company will now have real-time insights into inventory management, knowing exactly where merchandise is located and whether it’s owned by the retailer, at any moment, and covering an estimated 90 million pallets of inventory when at full scale.

The ambient IoT sensors Walmart uses capture signals about temperature, location, humidity, and dwell time. These signals are linked with the company’s advanced artificial intelligence systems, enabling the company to dramatically improve supply chain efficiency, inventory accuracy, and cold chain compliance.

“We expect to be active in about 500 Walmart locations by the end of the year, with plans for national expansion in 2026,” said Greg Cathey, senior vice president of transformation and innovation at Walmart. The rollout will cover 4,600 Walmart Supercenters, Neighborhood Markets, and more than 40 distribution centers, generating high-resolution supply chain data that feeds into Walmart’s AI systems, he said.

“This data provides proof of delivery, improves replenishment decisions, and lets us know where our items are in real time,” Cathey said. “By combining continuous sensing with AI, we’re moving from probabilistic predictions to precision decision-making.”

Greater visibility into supply chain

What makes the addition of ambient IoT sensors significant is it provides a new stream of data into AI systems, enabling them to be even more effective in giving Walmart greater visibility into supply chain operations.

The technology initiative is already making a significant impact by eliminating some manual tasks and providing automated alerts, Cathey said. “Associates no longer need to perform time-consuming checks to locate items,” he said. “Automated alerts now flag this information in real time, allowing associates to act faster and dedicate more time to serving customers.”

The enhanced visibility into the supply chain is also helping to resolve inventory discrepancies, allowing improved customer experiences.

While Cathey did not disclose specific figures such as cost savings, Walmart is anticipating gains from higher supply chain efficiency, improved inventory accuracy, reduced manual tasks for associates, and the ability to get items on shelves more quickly. “Customers [will] benefit from better product availability and consistency,” he said.

“AI system performance is predicated on its training data. The better the data, the better the AI performance,” said Julien Bellanger, president of Wiliot. “Supply chain AI has long been fueled by inherently out-of-date data — or forecasted data that represents projections rather than reality.”

Ambient IoT is changing this model, Bellanger said, by fueling AI with data that reflects what’s actually happening throughout the supply chain.

“We have been here before; Walmart was an early adopter of RFID back in 2004 when it was supposed to provide much the same functionality,” said Bill Ray, distinguished vice president, analyst and chief of research at research firm Gartner. “However, this time the cost of the tags is much lower, and that will be a tipping point.”

Ray says it’s important to note that the value of such IoT systems is already known. “The business models have been well studied and evaluated, when RFID was first touted as the solution to supply chain problems,” he said. “RFID has had an enormous impact, but the cost of the tags prevented the transformation it had promised. The industry has been able to integrate the new, lower-cost tags into the same value models, and come up with positive answers.”

Gartner has been tracking Wiliot for a long time. “The question was never if the technology could deliver on its promise. The question was if Wiliot could reliably scale production without compromising tag performance or price, and if it could integrate with existing supply chain systems. This announcement tells us that Walmart is convinced it can, now Wiliot will have to prove it,” Ray said.

“Ambient IoT just works,” Cathey said. “It doesn’t require wanding or scanning. It lets our associates do what they do, and they can focus on doing their jobs safely and efficiently while providing continuous, real-time visibility into our supply chain.”

Ambient IoT got a boost earlier this year when a new business alliance was created to develop and promote an open, multi-standard ecosystem for ambient IoT manufacturers, suppliers, integrators, operators, users, and customers, based on next-generation, battery-free ambient IoT standards.

By focusing on advanced communication technologies, the alliance is seeking to overcome the limitations of traditional battery-powered IoT devices, promoting more sustainable and efficient products.