Amazon's Million-Robot Fleet Grows as Research Shows Mixed Impact on Workers

Amazon now operates more robots than any other company in the world, with more than 1 million machines working in warehouses around the clock to support tens of millions of same-day and one-day deliveries each day. Despite this automation, the company remains the second-largest corporate employer globally, with more than 1.5 million full-time and part-time human workers according to its 2025 annual report.

Expanding the Robot Fleet

Amazon's robotic era began with the 2012 acquisition of Kiva Systems, which was renamed Amazon Robotics and pioneered wheeled mobile robots that bring racks of items to workers. The company now manufactures robots primarily in Massachusetts and plans new production factories in Austin, Texas, and Greenwood, Indiana, to churn out even more machines.

Most of the fleet consists of wheeled mobile robots. Amazon says its Sequoia system can identify and store items up to 75 percent faster, while Hercules and the larger Titan robots retrieve tall shelving units called pods. The newest mobile robot, Proteus, uses sensors to operate safely around humans and other objects. To prevent robotic traffic jams in narrow lanes between storage pods, Amazon coordinates its robots with a suite of AI foundation models collectively named DeepFleet.

Robotic Arms Move In

Amazon expects to more than double its existing fleet of robotic arms this year, building on a current deployment described as being in the single-digit thousands. Robin, the first arm developed in-house, began testing in 2021 and debuted at a facility in Lakeland, Florida, in 2022, using eight suction cups and machine learning that raised picking success to 93.73 percent. Cardinal, operating in Nashville, Tennessee, since November 2022, packs packages weighing up to 50 pounds into wheeled carts. Sparrow handles hundreds of millions of product variations using foundation models, while Vulcan, deployed in Spokane, Washington, and Hamburg, Germany, starting in 2025, adds force feedback sensors that provide a sense of touch and is expected to scale up in 2027.

The Human Impact

Amazon says robots take on the toughest, highest-risk tasks and cites a 43 percent improvement in its Global Recordable Incident Rate since 2019, alongside a 70 percent improvement in its Lost Time Incident rate. Yet research tells a more complex story. A study published in ILR Review in April 2025, drawing on weekly data from more than 150 warehouses from 2016 through 2019, found a 40 percent decrease in severe injuries at robotic fulfillment centers but a 77 percent increase in less severe injuries linked to repetitive strain, driven by faster pick rates. Labor advocacy groups and a 2024 Senate investigation led by Sen. Bernie Sanders have also pointed to higher injury rates tied to automation.

The Future of Work

Amazon says fulfillment centers with advanced robotics require 30 percent more employees in reliability, maintenance, and engineering roles, and it has grown its number of robotic maintenance technicians by over 30 percent. However, an October 2025 New York Times report on internal strategy documents suggested the robotics push could reduce projected US hiring needs by more than 160,000 people by 2027 and 600,000 by 2033, though an Amazon spokesperson said the documents reflected the views of just one group inside the company. With the Amazon Labor Union, organized in Staten Island in April 2022, pushing a Safety Bill of Rights, the debate over automation's toll on workers is likely to continue.

Sources: Arstechnica