animation-fill-mode

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use 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 spec changes.

Summary

The animation-fill-mode CSS property specifies how a CSS animation should apply styles to its target before and after it is executing.

Syntax

Formal syntax: <single-animation-fill-mode>#
animation-fill-mode: none
animation-fill-mode: forwards
animation-fill-mode: backwards
animation-fill-mode: both

The # indicates that several values may be given, separated by commas.
Each applies to the animation defined in the same order in animation-name.
animation-fill-mode: none, backwards
animation-fill-mode: both, forwards, none

Values

none
The animation will not apply any styles to the target before or after it is executing.
forwards
The target will retain the computed values set by the last keyframe encountered during execution. The last keyframe encountered 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
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 of 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.

Example

You can see the effect of animation-fill-mode in the following example.  For animations that run for an infinite time, you might want them to end on the last state rather than the first.

HTML content

<p>Move your mouse over the grey box</p>
<div class="demo">
  <div class="grows">This just grows</div>
  <div class="growsandstays">This grows and stays big</div>
</div>

CSS content

.demo {
  border-top: 100px solid #ccc;
  height: 300px;
  font-family: sans-serif;
}
@keyframes grow {
    0% { font-size: 0 }
    100% { font-size: 40px }
}
@-webkit-keyframes grow {
    0% { font-size: 0 }
    100% { font-size: 40px }
}
.demo:hover .grows {
    animation-name: grow;
    animation-duration: 3s;
    -webkit-animation-name: grow;
    -webkit-animation-duration: 3s;
}
.demo:hover .growsandstays {
    animation-name: grow;
    animation-duration: 3s;
    animation-fill-mode: forwards;
    -webkit-animation-name: grow;
    -webkit-animation-duration: 3s;
    -webkit-animation-fill-mode: forwards;
}

Specifications

Specification Status Comment
CSS Animations Working Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes)-webkit 5.0 (5.0)-moz
16.0 (16.0)
10 12-o
12.10 #
4.0-webkit
Feature Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support ? 5.0 (5.0)-moz
16.0 (16.0)
? ? ?

See also

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