KeyframeEffect: composite property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨September 2022⁩.

The composite property of a KeyframeEffect resolves how an element's animation impacts its underlying property values.

Value

To understand these values, take the example of a keyframeEffect value of blur(2) working on an underlying property value of blur(3).

replace: The keyframeEffect overrides the underlying value it is combined with: blur(2) replaces blur(3).
add: The keyframeEffect is added to the underlying value with which it is combined (aka additive): blur(2) blur(3).
accumulate: The keyframeEffect is accumulated on to the underlying value: blur(5).