Change android resolution without “root”

On Your phone

Settings > About Phone > Build number > Tap it 7 times to become developer.
Settings > Developer Options > USB Debugging.

 

On Your PC or Mac

Install ADB (http://developer.android.com/tools/help/adb.html)

From your shell/console digit adb shell wm size widhtPXxheightPX

 

Nexus 5, 5X and 6P example resolution:

adb shell wm size 1800×3200
adb shell wm size 1980×3520
adb shell wm size 2025×3600
adb shell wm size 2160×5120
adb shell wm size 2250×4000
adb shell wm size 2646×4704
adb shell wm size 2880×5120

 

Xiaomi mi mix example resolution:

adb shell wm size 1370×2600