KeyframeEffect: getKeyframes() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2020.

The getKeyframes() method of a KeyframeEffect returns an Array of the computed keyframes that make up this animation along with their computed offsets.

Syntax

getKeyframes()

Return value

Returns a sequence of objects with the following format:

property value pairs

As many property value pairs as are contained in each keyframe of the animation.

offset

The offset of the keyframe specified as a number between 0.0 and 1.0 inclusive or null. This is equivalent to specifying start and end states in percentages in CSS stylesheets using @keyframes. This will be null if the keyframe is automatically spaced.

computedOffset

The computed offset for this keyframe, calculated when the list of computed keyframes was produced. Unlike offset, above, the computedOffset is never null.

easing

The easing function used from this keyframe until the next keyframe in the series.

composite

The KeyframeEffect.composite operation used to combine the values specified in this keyframe with the underlying value. This will be absent if the composite operation specified on the effect is being used.

Examples

In the following example, we can inspect the rolling animation to see its keyframes using the getKeyframes() method:

js
const emoji = document.querySelector("div"); // element to animate

const rollingKeyframes = new KeyframeEffect(
  emoji,
  [
    { transform: "translateX(0) rotate(0)" }, // keyframe
    { transform: "translateX(200px) rotate(1.3turn)" }, // keyframe
  ],
  {
    // keyframe options
    duration: 2000,
    direction: "alternate",
    easing: "ease-in-out",
    iterations: "Infinity",
  },
);

const rollingAnimation = new Animation(rollingKeyframes, document.timeline);
rollingAnimation.play();

// Array [ {…}, {…} ]
console.log(rollingAnimation.effect.getKeyframes());

html

body {
  box-shadow: 0 5px 5px pink;
}

div {
  width: fit-content;
  margin-left: calc(50% - 132px);
  font-size: 64px;
  user-select: none;
  margin-top: 1rem;
}