ViewTimeline

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

TheViewTimeline interface of theWeb Animations API represents a view progress timeline (seeCSS scroll-driven animations for more details).

Pass aViewTimeline instance to theAnimation() constructor or theanimate() method to specify it as the timeline that will control the progress of the animation.

Constructor

ViewTimeline(): Creates a newViewTimeline object instance.

Instance properties

This interface also inherits the properties of its parent,ScrollTimeline.

subjectRead only: Returns a reference to the subject element whose visibility within its nearest ancestor scrollable element (scroller) is driving the progress of the timeline and therefore the animation.
startOffsetRead only: Returns aCSSNumericValue representing the starting (0% progress) scroll position of the timeline as an offset from the start of the overflowing section of content in the scroller.
endOffsetRead only: Returns aCSSNumericValue representing the ending (100% progress) scroll position of the timeline as an offset from the start of the overflowing section of content in the scroller.

Instance methods

This interface inherits the methods of its parent,ScrollTimeline.

In this example, we animate an element with aclass ofsubject along a view progress timeline — it animates when moved upwards through the document as it scrolls. We also output thesubject,startOffset, andendOffset values to an output element in the top-right corner.

HTML

The HTML for the example is shown below.

html

<div>  <h1>Content</h1>  <p>    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod    tempor incididunt ut labore et dolore magna aliqua. Risus quis varius quam    quisque id. Et ligula ullamcorper malesuada proin libero nunc consequat    interdum varius. Elit ullamcorper dignissim cras tincidunt lobortis feugiat    vivamus at augue.  </p>  <p>    Dolor sed viverra ipsum nunc aliquet. Sed risus pretium quam vulputate    dignissim. Tortor aliquam nulla facilisi cras. A erat nam at lectus urna    duis convallis convallis. Nibh ipsum consequat nisl vel pretium lectus.    Sagittis aliquam malesuada bibendum arcu vitae elementum. Malesuada bibendum    arcu vitae elementum curabitur vitae nunc sed velit.  </p>  <div></div>  <p>    Adipiscing enim eu turpis egestas pretium aenean pharetra magna ac. Arcu    cursus vitae congue mauris rhoncus aenean vel. Sit amet cursus sit amet    dictum. Augue neque gravida in fermentum et. Gravida rutrum quisque non    tellus orci ac auctor augue mauris. Risus quis varius quam quisque id diam    vel quam elementum. Nibh praesent tristique magna sit amet purus gravida    quis. Duis ultricies lacus sed turpis tincidunt id aliquet. In egestas erat    imperdiet sed euismod nisi. Eget egestas purus viverra accumsan in nisl nisi    scelerisque. Netus et malesuada fames ac.  </p>  <div></div></div>

CSS

The CSS for the example looks like this:

css

.subject {  width: 300px;  height: 200px;  margin: 0 auto;  background-color: deeppink;}.content {  width: 75%;  max-width: 800px;  margin: 0 auto;}.output {  position: fixed;  top: 5px;  right: 5px;}p,h1,div {  font-family: "Helvetica", "Arial", sans-serif;}h1 {  font-size: 3rem;}p {  font-size: 1.5rem;  line-height: 1.5;}

JavaScript

In the JavaScript, we grab references to thesubject andoutput<div>s, then create a newViewTimeline, associating it with thesubject element to specify that the timeline progress is based on this element's visibility through its scrolling ancestor, setting ablock axis, and settinginset values to adjust the position of the box in which the subject is deemed to be visible.

We then animate thesubject element with the Web Animations API. Last of all, we display thesubject,startOffset, andendOffset values in theoutput element.

const subject = document.querySelector(".subject");const output = document.querySelector(".output");const timeline = new ViewTimeline({  subject,  axis: "block",  inset: [CSS.px("200"), CSS.px("300")],});subject.animate(  {    opacity: [0, 1],    transform: ["scaleX(0)", "scaleX(1)"],  },  {    fill: "both",    timeline,  },);output.textContent += `Subject element: ${timeline.subject.nodeName}, `;output.textContent += `start offset: ${timeline.startOffset}, `;output.textContent += `end offset: ${timeline.endOffset}.`;

Result

Scroll to see the subject element being animated.

Specifications

Specification
Scroll-driven Animations # viewtimeline-interface

Browser compatibility

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This page was last modified onNov 7, 2025 byMDN contributors.

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