The Sony Xperia XZ Premium is marketed as the first smartphone with a 4K HDR display in the world. We believe it is and is currently one of the best because the brand is popular for its Bravia TV products with very crisp displays. It’s already expected that the company will bring one of its best technologies to smaller devices as hi-res displays are in demand. For others, it’s already a necessity especially since more cameras are able to support 4K now.
The new Xperia flagship doesn’t use UHD all the time. This means that videos aren’t displayed in 4K as they should. Default view is 1080p Full HD but if you want 4K to be displayed all the time, you better adjust your display and settings by first installing an Android SDK to change the resolution to 4K.
Get the ADB tool. Run the ADB in the OS’ shell and change size to 2160 x 3840. Set the density to ‘wm density 820’. Running display in 4K makes the Xperia XZ Premium a more worthy choice. If you want to switch back to Full HD, you can just choose wm size setting to 1080 x 1920.
Android Kosmos shared this trick for XZ Premium phone owners. Note that there will be no evident battery drain even if you use the 4K HDR display all the time.