The Sony Xperia Z4 is the manufacturer's first premium smartphone of 2015, announced first for the Japanese market. The Xperia Z4 continues Sony's "Omnibalance" design language seen in other Xperia Z products, and offers modestly upgraded internals and a thinner design compared to its predecessor, the Xperia Z3. It's powered by a Qualcomm Snapdragon 810 processor, sports a 20.7-megapixel main camera like previous Z-series phones, along with an upgraded 5.1-megapixel selfie camera. The battery has taken a hit compared to the Z3 though, going from 3,100mAh to 2,930mAh.
The Sony Xperia Z4 will launch first in Japan in summer 2015. No "Compact" version of the phone has been announced as yet.