What was the increase in RF front-end revenues year over year in the second quarter of 2021
eas to name a few include smart energy, tracking, metering, industrial handhelds, retail, automation, and autonomous drones.
As connected IoT edge devices get scale and provide access to the data and contextual information that is fueling the exponential growth projections of cloud ecosystems, we're increasingly confident in the long-term growth opportunity for our IoT business. Turning to our licensing business. Our second-quarter results reflect the strength of our unmatched patent portfolio value. We are the global 5G IP leader with more than 130 5G license agreements signed to date, up from over 120 last quarter with all major handset manufacturers around the globe licensed.
We continue to develop and patent new essential innovations for future releases of 5G, which we expect to have a longer life cycle than prior generations due to its impact on multiple industries. We believe that our model of early research and development, consistent standards leadership, flexible licensing, and global implementation support will continue to add value to our partners and stockholders for years to come. Overall, we continue to see unprecedented demand across all of our technologies and businesses as the current environment is accelerating the scale of connectivity and processing at the edge. Despite the industrywide semiconductor supply shortage, we're utilizing our scale and working across our entire global supply chain to maximize our ability to capture this opportunity.
We expect material improvements by the end of the calendar year due to planned capacity builds and multi-sourcing initiatives. As one of the leading drivers of advanced semiconductor technology platforms, we're also excited to see more foundry investment in the United States consistent with the United States government's strategic priorities. Finally, we're extremely proud of our collaboration with NASA's Jet Propulsion Laboratory on Ingenuity, the Mars helicopter powered by Snapdragon. Snapdragon made it to Mars and helped power the first-ever autonomous flight on another planet.
This is yet another example of our ingenuity. I would now like to turn the call over to Akash.
Akash Palkhiwala -- Chief Financial Officer
Thank you, Cristiano, and good afternoon, everyone. We are pleased to report strong second-quarter results with non-GAAP revenues of $7.9 billion and non-GAAP EPS of $1.90, which was $0.15 above the high end of our guidance range. These results reflect year-over-year increases of 52% and 116% in revenue and EPS, respectively, driven by strength across QTL and QCT. In QTL, we recorded revenues of $1.6 billion and EBT margins of 74%, both above the high end of our guidance range.
The outperformance was primarily driven by stronger handset shipments, especially in China. In addition, our results include a benefit of approximately $80 million from adjustments to prior-quarter royalty estimates. In QCT, we delivered revenues of $6.3 billion and EBT of $1.6 billion. On a year-over-year basis, revenues were up 53% while EBT grew 137%, delivering on our commitment to increase operating leverage.
We achieved the high end of our guidance range with EBT margins of 25%. This reflects our strong operating performance driven by favorable product mix and gross margins, which more than offset a reduction in the orders within the quarter by a global handset OEM. RF front-end revenues increased 39% year over year to approximately $900 million on the strength of our product portfolio across 4G, 5G sub-6, and 5G millimeter wave. 5G millimeter wave products accounted for less than 20% of our second-quarter RF front-end revenues.
We expect millimeter wave deployments in other regions, such as China, to be a tailwind for long-term revenue growth. Automotive revenues of $240 million grew 40%, and IoT revenues of $1.1 billion grew 71% on a year-over-year basis as we continue to see strong momentum for our differentiated product portfolio. During the quarter, we completed the acquisition of NUVIA for a purchase price of $1.4 billion before working capital and other adjustmen
eas to name a few include smart energy, tracking, metering, industrial handhelds, retail, automation, and autonomous drones.
As connected IoT edge devices get scale and provide access to the data and contextual information that is fueling the exponential growth projections of cloud ecosystems, we're increasingly confident in the long-term growth opportunity for our IoT business. Turning to our licensing business. Our second-quarter results reflect the strength of our unmatched patent portfolio value. We are the global 5G IP leader with more than 130 5G license agreements signed to date, up from over 120 last quarter with all major handset manufacturers around the globe licensed.
We continue to develop and patent new essential innovations for future releases of 5G, which we expect to have a longer life cycle than prior generations due to its impact on multiple industries. We believe that our model of early research and development, consistent standards leadership, flexible licensing, and global implementation support will continue to add value to our partners and stockholders for years to come. Overall, we continue to see unprecedented demand across all of our technologies and businesses as the current environment is accelerating the scale of connectivity and processing at the edge. Despite the industrywide semiconductor supply shortage, we're utilizing our scale and working across our entire global supply chain to maximize our ability to capture this opportunity.
We expect material improvements by the end of the calendar year due to planned capacity builds and multi-sourcing initiatives. As one of the leading drivers of advanced semiconductor technology platforms, we're also excited to see more foundry investment in the United States consistent with the United States government's strategic priorities. Finally, we're extremely proud of our collaboration with NASA's Jet Propulsion Laboratory on Ingenuity, the Mars helicopter powered by Snapdragon. Snapdragon made it to Mars and helped power the first-ever autonomous flight on another planet.
This is yet another example of our ingenuity. I would now like to turn the call over to Akash.
Akash Palkhiwala -- Chief Financial Officer
 Thank you, Cristiano, and good afternoon, everyone. We are pleased to report strong second-quarter results with non-GAAP revenues of $7.9 billion and non-GAAP EPS of $1.90, which was $0.15 above the high end of our guidance range. These results reflect year-over-year increases of 52% and 116% in revenue and EPS, respectively, driven by strength across QTL and QCT. In QTL, we recorded revenues of $1.6 billion and EBT margins of 74%, both above the high end of our guidance range.
The outperformance was primarily driven by stronger handset shipments, especially in China. In addition, our results include a benefit of approximately $80 million from adjustments to prior-quarter royalty estimates. In QCT, we delivered revenues of $6.3 billion and EBT of $1.6 billion. On a year-over-year basis, revenues were up 53% while EBT grew 137%, delivering on our commitment to increase operating leverage.
We achieved the high end of our guidance range with EBT margins of 25%. This reflects our strong operating performance driven by favorable product mix and gross margins, which more than offset a reduction in the orders within the quarter by a global handset OEM. RF front-end revenues increased 39% year over year to approximately $900 million on the strength of our product portfolio across 4G, 5G sub-6, and 5G millimeter wave. 5G millimeter wave products accounted for less than 20% of our second-quarter RF front-end revenues.
We expect millimeter wave deployments in other regions, such as China, to be a tailwind for long-term revenue growth. Automotive revenues of $240 million grew 40%, and IoT revenues of $1.1 billion grew 71% on a year-over-year basis as we continue to see strong momentum for our differentiated product portfolio. During the quarter, we completed the acquisition of NUVIA for a purchase price of $1.4 billion before working capital and other adjustmen