Future CSS: Native scroll animations

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Linking animations to a user's scroll position is a common task for front-end developers, typically requiring a significant amount of JavaScript. However, did you know that you might soon be able to achieve this natively with CSS?

CSS Scroll-driven Animations are a new proposal for creating animations that are tied to the scroll offset of an element.

How can I use it?

Let's take a look at how you can use CSS Scroll-driven Animations in an example.


Scroll down

This first demo, shows a simple progress bar that scales in width as you scroll down the page. You'll recognise the @keyframe animation from regular CSS animations, but the magic happens in the animation-timeline and scroll-timeline properties.

Let's start with looking at the code. For simplicity, I've removed all of the other styles (like colours and layout), but if you want you can find the full code in the demo here.

.container {
  timeline-scope: --scale-progress;

.scrollContainer {
  scroll-timeline: --scale-progress block;

.progress {
  animation: scaleProgress linear;
  animation-timeline: --scale-progress;
  animation-duration: auto;

@keyframes scaleProgress {
  0% {
    transform: scaleX(0);
  100% {
    transform: scaleX(1);

Okay, so let's break it down.

The timeline-scope property is used to set a scope for the animation. As our progress element is outside the scroll container, we need to manually set the scope. If our progress element was inside the scroll container we wouldn't need to set this property.

The scroll-timeline property is used to link the animation to the scroll position of the element. In this case, we're linking it to the block axis, which means the animation will be triggered as the element scrolls vertically.

The animation-timeline property is used to link the animation to the timeline scope we set earlier. This must be on the same element as the animation property.

Support. Can you use it today?

Unfortunately, the spec is still in the early stages and is not yet fully supported by any major browser (as of May 2024), however you can still experiment with it in Chrome by enabling the #enable-experimental-web-platform-features flag.

Further Reading