Adaptive web design

This most often describes the use of a mobile and a desktop version of a page (or in most cases, the entire website), either of which is retrieved based on the user-agent defined in the HTTP GET request, which is known as dynamic serving.

Today the use of two separate static sites for mobile and desktop viewing is being largely phased out, with Server-side scripting instead utilized to serve dynamically generated pages or to dynamically decide which version of a static page to serve, although the use of independent sites for mobile and desktop can still be frequently observed.

The adaptive design will serve different versions of the page to different devices based on common screen sizes and resolutions.

The term was first coined by Aaron Gustafson in his 2011 book Adaptive Web Design: Crafting Rich Experiences with Progressive Enhancement.

Browsers of basic mobile phones do not understand JavaScript or media queries, so a recommended practice is to create a basic mobile layout and use progressive enhancement for smart phones, rather than rely on graceful degradation to make a complex, image-heavy site work.

The mobile versions were still usually "scaled-down" with lower quality images and sometimes lacked content such as videos in order to decrease loading time.

Designs were also influenced by the spread of touchscreen devices, with websites using larger links and buttons that make navigating using a finger as a pointer easier.