Android background image size in pixel

Try follow below android icon graphy size reference for various device screen resolutin.

                            ldpi     mdpi     hdpi     xhdpi    xxhdpi     xxxhdpi
Launcher And Home           36*36    48*48   72*72    96*96    144*144    192*192
Action Bar And Tab          24*24    32*32   48*48    64*64    96*96      128*128
Notification                18*18    24*24   36*36    48*48    72*72      96*96
Background                  320*426  320*470 480*640  720*1280 1080*1920  1440*2560

there is no full list of screen resolutions, there are no fixed values in pixels for ldpi, mdpi, hdpi,xhdpi and xxhdpi. Every android device may have different resolution. If you want to fill all resolutions you will have to create too many images. If you put them in your app, it will make the app size huge. Maybe a better approach is to use composite image for background.