Responsive design is taking the world by a storm and every team is converting their site to be on mobile or preparing to do that soon.
Few people however realize performance implications of this new approach to web development and one of the issues is images which represent more then 60% of all network payload and can congest wireless networks with data unnecessary for display on naturally smaller screens than desktop.
This issue gave birth to various Responsive Images techniques which are used to display “just right” size of the image for user’s device. There are several aspects of the issue that need to be considered, from formats and resolutions to content management and implementation code. When done wrong, performance can degrade much worse then original “desktop” approach, but with a few key features implemented right, can reduce payload size dramatically providing improved user experience.