--- layout: default title: Pixel Density --- # Pixel Density ## Device pixel ratio `dpr` The device pixel ratio is used to easily convert between CSS pixels and device pixels. This makes it possible to display images at the correct pixel density on a variety of devices such as Apple devices with Retina Displays and Android devices. You must specify either a width, a height, or both for this parameter to work. The default is 1. The maximum value that can be set for dpr is 8. ~~~ html <img src="kayaks.jpg?w=250&dpr=2"> ~~~ [](https://glide.herokuapp.com/1.0/kayaks.jpg?w=250&dpr=2)