The Complete Guide to Lazy Loading

Lazy loading images means loading artifacts such as images on websites asynchronously — that is, after the above-the-fold content is fully loaded, or even conditionally, only when they appear in the browser’s viewport. This means that if users don’t scroll all the way down, images placed at the bottom of the page won’t even be loaded. A number of websites use this approach, but it’s especially noticeable on image-heavy sites.

By postponing the loading of images that are not immediately required – or, in some cases, not loading them at all – the browser saves resources (bandwidth as well as CPU). The page loads faster and the user experience is improved as saved resources can be affected to more critical content. There are also server-side gains. The CPU and bandwidth required to delivered the resources are subjected to less stress, reducing the hosting and/or CDN costs.

This SlideShare explores the concept of Lazy Loading in brief.