Progressively enhanced animated content

I’ve read a lot of articles about using prefers-reduced-motion on the web; I’ve even written one of them!

I’m a big fan of Patrick H. Lauke’s progressively enhanced approach where instead of telling the browser “here’s an animated image, but don’t show it if the user has set reduced motion on their system”, we’re only serving the animation if:

• the user has an operating system and browser that is able to reduce motion
• the user hasn’t turned on the reduced motion setting

So instead of this SCSS, that I use to make the underscore on my logo blink:

.underscore {
  animation: blink 2s steps(20, start) infinite;

  @media screen and (prefers-reduced-motion: reduce) {
    animation: none;
  }
}

We’d write this:

@media screen and (prefers-reduced-motion: no-preference) {
  .underscore {
    animation: blink 2s steps(20, start) infinite;
  }
}

The crucial thing here is that users who can’t opt in to reducing animation won’t get the animation, where previously they got it whether they wanted it or not. Not very accessible!

The great news is that this approach extends to use within the <picture> element for animated content, as opposed to CSS-housed decoration. So, building on code from a Brad Frost blog post:

<picture>
    <source srcset="animated.gif" media="(prefers-reduced-motion: no-preference)"></source>
    <img srcset="static.jpg" alt="Description of the image" />
</picture>

I know we might be depriving some users of our lovely animations, but if we can’t be sure a user won’t have a bad experience with motion, we should be serving up static content.