This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.


The animation-timing-function CSS property specifies how a CSS animation should progress over the duration of each cycle. The possible values are one or several <timing-function>.

For keyframed animations, the timing function applies between keyframes rather than over the entire animation. In other words, the timing function is applied at the start of the keyframe and at the end of the keyframe.

An animation timing function defined within a keyframe block applies to that keyframe; otherwise. If no timing function is specified for the keyframe, the timing function specified for the overall animation is used.

It is often convenient to use the shorthand property animation to set all animation properties at once.

Initial valueease
Applies toall elements, ::before and ::after pseudo-elements
Computed valueas specified
Animation typediscrete
Canonical orderthe unique non-ambiguous order defined by the formal grammar


/* Keyword values */
animation-timing-function: ease;
animation-timing-function: ease-in;
animation-timing-function: ease-out;
animation-timing-function: ease-in-out;
animation-timing-function: linear;
animation-timing-function: step-start;
animation-timing-function: step-end;

/* Function values */
animation-timing-function: cubic-bezier(0.1, 0.7, 1.0, 0.1);
animation-timing-function: steps(4, end);

/* Multiple animations */
animation-timing-function: ease, step-start, cubic-bezier(0.1, 0.7, 1.0, 0.1);

/* Global values */
animation-timing-function: inherit;
animation-timing-function: initial;
animation-timing-function: unset;


Each <timing-function> represents the timing function to link to the corresponding property to animate, as defined in animation-property.

Note: When you specify multiple comma-separated values on an animation-* property, they will be assigned to the animations specified in the animation-name property in different ways depending on how many there are. For more information, read Setting multiple animation property values.

Formal syntax


<single-timing-function> = <single-transition-timing-function>

<single-transition-timing-function> = ease | linear | ease-in | ease-out | ease-in-out | step-start | step-end | steps(<integer>[, [ start | end ] ]?) | cubic-bezier(<number>, <number>, <number>, <number>)


See CSS animations for examples.


Specification Status Comment
CSS Animations
The definition of 'animation-timing-function' in that specification.
Working Draft Initial definition

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes)-webkit
5.0 (5.0)-moz
16.0 (16.0)[1]
10 12 -o
Feature Android Edge Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support (Yes)-webkit (Yes)-webkit
5.0 (5.0)-moz
16.0 (16.0)[1]
? 12-o (Yes)-webkit ?

[1] In addition to the unprefixed support, Gecko 44.0 (Firefox 44.0 / Thunderbird 44.0 / SeaMonkey 2.41) added support for a -webkit prefixed version of the property for web compatibility reasons behind the preference layout.css.prefixes.webkit, defaulting to false. Since Gecko 49.0 (Firefox 49.0 / Thunderbird 49.0 / SeaMonkey 2.46) the preference defaults to true.

See also