Tips for a crisp-looking wallpaper
Choose an image that suits both the aspect ratio and resolution of your screen. The listed alternatives are named by image width; they do not automatically match a particular phone or desktop. If your device needs a wider file than the options offered, try the original image.
For a lock screen, check whether the clock and notifications obscure the most important part of the artwork. For a desktop wallpaper, try Fill, Fit and Center to see which crop works best before keeping the change.