In this lesson, you'll learn how to use the loading="lazy" attribute available on images and iframes to lazily load below the fold images, which saves bandwidth and increases the load time performance of web pages. You'll also learn how to prevent images from lazy loading if necessary, and how to add lazy loading to responsive images as well. Lazy loading is supported in Chrome 76, and will be available in the next version of Edge and has public signals of support from Firefox, and Safari as well.
<!DOCTYPE html>
<style>
img {
border: 1px solid black;
display: block;
width: 400px;
height: 1000px;
}
</style>
<img loading="lazy" src="https://via.placeholder.com/400x1000"/>
<img loading="lazy" src="https://via.placeholder.com/400x1001"/>
<img loading="lazy" src="https://via.placeholder.com/400x1002"/>
<img loading="lazy" src="https://via.placeholder.com/400x1003"/>
<picture>
<source media="(min-width: 100px)" srcset="https://via.placeholder.com/1200x3000">
<img loading="lazy" src="https://via.placeholder.com/400x1004"/>
</picture>
<img loading="lazy"
srcset="https://via.placeholder.com/400x1005 400w, https://via.placeholder.com/800x2010 800w"/>
<iframe loading="lazy" src="http://example.com" width="400" height="400"></iframe>