animation-fill-mode

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

none

The animation will not apply any styles to the target when it's not executing. The element will instead be displayed using any other CSS rules applied to it. This is the default value.

forwards

The target will retain the computed values set by the last keyframe encountered during execution. The last keyframe depends on the value of animation-direction and animation-iteration-count:

animation-direction	animation-iteration-count	last keyframe encountered
normal	even or odd	100% or to
reverse	even or odd	0% or from
alternate	even	0% or from
alternate	odd	100% or to
alternate-reverse	even	100% or to
alternate-reverse	odd	0% or from

Animated properties behave as if included in a set will-change property value. If a new stacking context was created during the animation, the target element retains the stacking context after the animation has finished.

backwards

The animation will apply the values defined in the first relevant keyframe as soon as it is applied to the target, and retain this during the animation-delay period. The first relevant keyframe depends on the value of animation-direction:

animation-direction	first relevant keyframe
normal or alternate	0% or from
reverse or alternate-reverse	100% or to

both

The animation will follow the rules for both forwards and backwards, thus extending the animation properties in both directions.

animation-fill-mode = 
  <single-animation-fill-mode>#  

<single-animation-fill-mode> = 
  none       |
  forwards   |
  backwards  |
  both       

You can see the effect of animation-fill-mode in the following example. It demonstrates how you can make the animation remain in its final state rather than reverting to the original state (which is the default).

HTML

<p>Move your mouse over the gray box!</p>
<div class="demo">
  <div class="grows-and-stays">This grows and stays big.</div>
  <div class="grows">This just grows.</div>
</div>

CSS

.demo {
  border-top: 100px solid #ccc;
  height: 300px;
}

@keyframes grow {
  0% {
    font-size: 0;
  }
  100% {
    font-size: 40px;
  }
}

.demo:hover .grows {
  animation-name: grow;
  animation-duration: 3s;
}

.demo:hover .grows-and-stays {
  animation-name: grow;
  animation-duration: 3s;
  animation-fill-mode: forwards;
}

Result

See CSS animations for more examples.

• Using CSS animations
• JavaScript AnimationEvent API
• Other related animation properties: animation, animation-composition, animation-delay, animation-direction, animation-duration, animation-iteration-count, animation-name, animation-play-state, animation-timeline, animation-timing-function