As noted by Nicolas Lellouche, who writes for the French tech site NumbermaApple has updated its technical specifications pages for the iPhone 18 Pro and iPhone 18 Pro Max to clarify which models are equipped with its new C2 cellular modem and where.
Apple now says the iPhone 18 Pro has a C2 modem worldwide, while the iPhone 18 Pro Max uses the chip in every country except the United States.
According to a tipster known as @itspdfu, who has been digging into Apple’s software updates in recent weeks, iOS 27 code reveals that the iPhone 18 Pro Max is equipped with a Qualcomm modem instead of the C2 chip in the United States.
Apple has yet to provide an explanation for this modem difference, so we can only speculate for now. In 2023, Qualcomm announced that it would supply Apple with smartphone modems until 2026, so perhaps Apple is equipping the US version of the iPhone 18 Pro Max with a Qualcomm modem to at least honor this agreement.
Apple’s C2 modem supports ultra-fast mmWave 5G technology in the United States, unlike its previous generation C1 and C1X modems. Qualcomm modems in the iPhone 12 and newer models already support mmWave 5G in the US, so Apple is catching up here. Apple said the C2 delivers “significantly faster” downloads compared to the C1X while consuming 15 percent less power.
Apple’s first-generation C1 modem debuted on the iPhone 16e in February 2025, and the second-generation C1X debuted on the iPhone Air in September 2025. Now, the third-generation C2 modem has arrived in the iPhone 18 Pro models, except for the iPhone 18 Pro Max in the US as mentioned, as Apple’s transition away from Qualcomm continues.
It’s unclear which Qualcomm modem is in the US units of the iPhone 18 Pro Max, but the Snapdragon X85 is the most likely. Over the next few weeks, real-world benchmarks should show how the C2 and Snapdragon X85 compare.
Apple’s foldable iPhone Duo uses the C2 modem worldwide.
