If we talk about specs then Sony Xperia Z3 Compact has 4.6-inch 720p Triluminos display with X-Reality engine, under the hood it is powered by the same 2.5GHz Snapdragon 801 quad-core processor with Adreno 330 GPU and 2GB of RAM, other specs remains same as of Sony Xperia Z3 like :-
Has 20.7-megapixel autofocus rear camera with LED flash and Exmor RS which is capable of recording 4K videos at front it has a 2.2-megapixel front facing camera. For connectivity it includes Bluetooth, Wi-Fi with hotspot, 3G, 4G LTE (in select markets), GPS/ A-GPS, Glonass, Micro-USB, DLNA, and NFC.
It houses a 2600mAh battery which can deliver up to 14 hours of talk time and 920 hours of standby time. Sony Xperia Z3 Compact carry IP65/IP68 ratings for dust-proof and waterproof certification.