The animation-duration CSS property sets the length of time that an animation takes to complete one cycle.

Try it

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


/* Single animation */
animation-duration: auto; /* Default */
animation-duration: 6s;
animation-duration: 120ms;

/* Multiple animations */
animation-duration: 1.64s, 15.22s;
animation-duration: 10s, 35s, 230ms;

/* Global values */
animation-duration: inherit;
animation-duration: initial;
animation-duration: revert;
animation-duration: revert-layer;
animation-duration: unset;



For time-based animations, auto is equivalent to a value of 0s (see below). For CSS scroll-driven animations, auto fills the entire timeline with the animation.


The time that an animation takes to complete one cycle. This may be specified in either seconds (s) or milliseconds (ms). The value must be positive or zero and the unit is required.

If no value is provided, the default value of 0s is used, in which case the animation still executes (the animationStart and animationEnd events are fired). Whether or not the animation will be visible when the duration is 0s will depend on the value of animation-fill-mode, as explained below:

  • If animation-fill-mode is set to backwards or both, the first frame of the animation as defined by animation-direction will be displayed during animation-delay countdown.
  • If animation-fill-mode is set to forwards or both, the last frame of the animation will be displayed, as defined by animation-direction, after the animation-delay expires.
  • If animation-fill-mode is set to none, the animation will have no visible effect.

Note: Negative values are invalid, causing the declaration to be ignored. Some early, prefixed, implementations may consider them as identical to 0s.

Note: When you specify multiple comma-separated values on an animation-* property, they are applied to the animations in the order in which the animation-names appear. For situations where the number of animations and animation-* property values do not match, see Setting multiple animation property values.

Note: When creating CSS scroll-driven animations, specifying an animation-duration value in seconds or milliseconds doesn't really make sense. In tests, it seemed to have no effect on scroll progress timeline animations, while on view progress timeline animations it seemed to push the animation to happen nearer the end of the timeline. However, Firefox requires an animation-duration to be set for it to successfully apply the animation. You are therefore advised to set animation-duration to 1ms so that animations will work in Firefox, but the effect is not altered too much by it.

Formal definition

Initial value0s
Applies toall elements, ::before and ::after pseudo-elements
Computed valueas specified
Animation typeNot animatable

Formal syntax

animation-duration = 
<time [0s,∞]>#


Setting animation duration

This animation has an animation-duration of 0.7 seconds.


<div class="box"></div>


.box {
  background-color: rebeccapurple;
  border-radius: 10px;
  width: 100px;
  height: 100px;

.box:hover {
  animation-name: rotate;
  animation-duration: 0.7s;

@keyframes rotate {
  0% {
    transform: rotate(0);
  100% {
    transform: rotate(360deg);


Hover over the rectangle to start the animation.

See CSS animations for more examples.


CSS Animations Level 1
# animation-duration

Browser compatibility

BCD tables only load in the browser

See also