Which smartphone was the first to feature a 64-bit processor?

The iPhone 5S was the first smartphone to feature a 64-bit processor. Its Apple A7 system-on-chip, introduced in September 2013, used a 64-bit ARMv8-A architecture and was paired with the M7 motion coprocessor.

The change was notable because most smartphones at the time used 32-bit processors. Apple said the A7 could deliver up to twice the CPU and graphics performance of the preceding A6, while 64-bit support gave software access to wider registers and a larger address space. iOS 7 and Apple's built-in apps were prepared for 64-bit operation when the phone shipped.

The iPhone 5S also introduced Touch ID, a fingerprint sensor built into a redesigned home button, and a gold color option. The iPhone 5C released alongside it retained older 32-bit hardware, so the two 2013 models were not equivalent internally. Qualcomm and Android manufacturers later followed with 64-bit smartphone chips, but the iPhone 5S made the first mainstream smartphone debut in this category.