A purported spec sheet of the Sony Xperia XZ3 has leaked in Japan, ushering the phone into the rumor mill. The sheet points to a meek update over the Xperia XZ2 - a slightly bigger battery, more RAM (6GB) and the dual camera from the Xperia XZ2 Premium - 19 MP (25mm, f/1.8, 1/2.3" 1.22µm) + 12 MP B/W (f/1.6, 1/2.3", 1.55µm). The selfie camera seems to be the same 13MP f/2.0 snapper. The Xperia XZ3 is also slightly thinner and lighter than Sony's current phone. If these leaked specs turn out truthful, then the Xperia XZ3 will retain the 5.7-inch 2160x1080 LCD and Snapdragon 845...
Source: https://www.gsmarena.com/alleged_sony_xperia_xz3_specs_leak__an_xz2_with_xz2_premium_dual_camera-news-31553.php