Web/API/EffectTiming/easing

This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

The EffectTiming dictionary's easing property in the Web Animations API specifies the timing function used to scale the time to produce easing effects, where easing is the rate of the animation's change over time.

Element.animate(), KeyframeEffectReadOnly(), and KeyframeEffect() all accept an object of timing properties including easing. The value of easing corresponds directly to AnimationEffectTimingReadOnly.easing in timing objects returned by AnimationEffectReadOnly, KeyframeEffectReadOnly, and KeyframeEffect.

Syntax

var timingProperties = {
  easing: single-transition-timing-function
}

timingProperties.easing = single-transition-timing-function

Value

A string defining the timing function to use for easing transitions during the animation process. Accepts several pre-defined DOMString values, a steps() timing function like steps(5, end), or a custom cubic-bezier value like cubic-bezier(0.42, 0, 0.58, 1). Defaults to linear. Available values include:

linear: A constant rate of change, neither accelerating nor deccelerating.
cubic-bezier(<number>, <number>, <number>, <number>): [[File:../../../../../../www.w3.org/TR/css-easing-1/cubic-bezier-timing-curve.html|A diagram showing the points of a cubic bezier timing function.]] Specifies a cubic Bézier timing function. The four numbers specify points P1 and P2 of the curve as (x1, y1, x2, y2). Both x values must be in the range [0, 1] or the definition is invalid.
ease: A decelerated rate of change, going from fast to slow. Equivalent to cubic-bezier(0.25, 0.1, 0.25, 1).
ease-in: An accelerated rate of change, going from slow to fast. Equivalent to cubic-bezier(0.42, 0, 1, 1).
ease-out: Another decelerated rate of change, going from fast to slow. Equivalent to cubic-bezier(0, 0, 0.58, 1).
ease-in-out: This rate of change speeds up in the middle. Equivalent to cubic-bezier(0.42, 0, 0.58, 1).
frames(<integer>): Specifies a frames timing function, which breaks the animation down into a number of equal time intervals but also displays the start (0%) and end (100%) states for an equal amount of time to the other intervals. The browser flips to a different static frame when each interval is reached, rather than animating smoothly. See GitHub for a [[../../../../../../../mdn.github.io/css-examples/animation-frames-timing-function/index-waa|simple example]] that illustrates the difference between steps() and frames().
steps(<integer>[, [ start | end ] ]?): [[File:../../../../../../www.w3.org/TR/css-easing-1/step-timing-func-examples.html|A diagram of the various steps timing functions.]] Specifies a step timing function, which breaks the animation down into a number of equal time intervals. The browser flips to a different static frame when each interval is reached, rather than animating smoothly. The first parameter specifies the number of intervals in the function. It must be a positive integer (greater than 0). The second parameter, which is optional, specifies the point at which the change of values occur within the interval. If the second parameter is omitted, it is given the value end.
step-start: Equivalent to steps(1, start)
step-end: Equivalent to steps(1, end).

Examples

In the Red Queen's Race example, we animate Alice and the Red Queen by passing an easing of steps(7, end) to animate():

// Define the key frames
var spriteFrames = [
  { transform: 'translateY(0)' },
  { transform: 'translateY(-100%)' }   
];

// Get the element that represents Alice and the Red Queen
var redQueen_alice_sprite = document.getElementById('red-queen_and_alice_sprite');

// Animate Alice and the Red Queen using steps()
var redQueen_alice = redQueen_alice_sprite.animate(
spriteFrames, {
  easing: 'steps(7, end)',
  direction: "reverse",
  duration: 600,
  playbackRate: 1,
  iterations: Infinity
});

Specifications

Specification	Status	Comment
Web AnimationsThe definition of 'easing' in that specification.	Working Draft	Editor's draft.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`easing` Experimental'	Chrome Full support 52	Edge Full support ≤79	Firefox Full support 63	IE No support No	Opera Full support Yes	Safari No support No	WebView Android Full support 52	Chrome Android Full support 52	Firefox Android Full support 63	Opera Android Full support Yes	Safari iOS No support No	Samsung Internet Android Full support 6.0
`jump-` keywords for `steps()`	Chrome Full support 52	Edge Full support ≤79	Firefox Full support 65	IE No support No	Opera No support No	Safari No support No	WebView Android Full support 52	Chrome Android Full support 52	Firefox Android Full support 65	Opera Android Full support 55	Safari iOS No support No	Samsung Internet Android Full support 12.0

Legend

Full support: Full support
No support: No support
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.