CSS skeleton loading screen animation

In this tutorial well be using CSS to create an animated skeleton loading screen. Skeleton loading screens provide an approximate representation of a site layout while a page is loading data. This lets users know that the content is loading and unlike a full page loading screen individual elements of the page can be loading in gradually using this technique.

Today well create a skeleton screen for a video card component thatll look like this:

For the HTML we only require is single empty <div> element:

<div class="video"></div>`

Now we can start with the CSS. Well use the :empty pseudo-class that will only display the skeleton when the video <div> is empty (including whitespace) and disappear once content has been injected. Developers often use a toggle class to achieve the same effect but this solution is much simpler:

.video:empty {  width: 315px;  height: 250px;   cursor: progress; }

The video component contains 4 elements, a semi transparent overlay that well animating to give the illusion of data being fetched, then skeleton representations of a thumbnail, avatar and title text. These 4 elements are created using background CSS gradients. For the skeleton elements we achieve a solid color by using the same color value for both gradient endpoints:

background:   linear-gradient(0.25turn, transparent, #fff, transparent),  linear-gradient(#eee, #eee),  radial-gradient(38px circle at 19px 19px, #eee 50%, transparent 51%),  linear-gradient(#eee, #eee);background-repeat: no-repeat;

Now we need to define the size for each of these elements:

background-size: 315px 250px, 315px 180px, 100px 100px, 225px 30px;

Next specify the keyframe animation to be used:

animation: loading 1.5s infinite;

Heres what the complete .video class looks like:

.video:empty {  width: 315px;  height: 250px;   cursor: progress;   background:     linear-gradient(0.25turn, transparent, #fff, transparent),    linear-gradient(#eee, #eee),    radial-gradient(38px circle at 19px 19px, #eee 50%, transparent 51%),    linear-gradient(#eee, #eee);    background-repeat: no-repeat;  background-size: 315px 250px, 315px 180px, 100px 100px, 225px 30px;   background-position: -315px 0, 0 0, 0px 190px, 50px 195px;   animation: loading 1.5s infinite;}

Final thing to do is add the @keyframes animation to the first gradient by shifting the x-axis of the background position to the right hand edge of the parent element. You could also experiment with animating the opacity here for extra visual appeal:

@keyframes loading {    to {    background-position: 315px 0, 0 0, 0 190px, 50px 195px;  }}

You can now test this code out in a browser, heres what it should look like:

Hopefully you found this tutorial useful and it serves as a good starting point for building all types of different skeleton loading screens. If you are having trouble figuring out the whole background gradient thing try starting with a single skeleton element before adding additional elements.