CSS animation-fill-mode

The CSS animation-fill-mode property allows you to define what values are applied by the animation outside the time it is executing. This can be before the animation has been applied, or after it has finished running.

Syntax

animation-fill-mode: [ none | forwards | backwards | both ] [, [ none | forwards | backwards | both ] ]*

Possible Values

none
Specifies that no styles will be applied to the element before or after the animation is executing.
forwards
Specifies that the animation will apply the property values defined in its last executing keyframe after the final iteration of the animation, until the animation style is removed.
backwards
Specifies that the animation will apply the property values defined in its 0% or from keyframe as soon as the animation is applied, during the period defined by animation-delay.
both
Specifies that the animation will follow the rules for both forwards and backwards (i.e. it will extend the animation properties in both directions).

In addition, all CSS properties also accept the following CSS-wide keyword values as the sole component of their property value:

initial
Represents the value specified as the property's initial value.
inherit
Represents the computed value of the property on the element's parent.
unset
This value acts as either inherit or initial, depending on whether the property is inherited or not. In other words, it sets all properties to their parent value if they are inheritable or to their initial value if not inheritable.

Basic Property Information

Initial Value
none
Applies To
All elements, and the :before and :after pseudo elements
Inherited?
No
Media
Visual

Example Code

Basic CSS

animation-fill-mode: backwards;

Working Example within an HTML Document

<!DOCTYPE html>
<title>Example</title>
<style>
.springy-text {
  color: black;
  animation-name: springy-text;
  animation-duration: 1s;
  animation-timing-function: ease;
  animation-delay: 0s;
  animation-iteration-count: 1;
  animation-direction: normal;
  animation-fill-mode: forwards;
}
@keyframes springy-text {
  0%   {
    letter-spacing: 1.2em;
    color: white;
  }
  100%   {
    letter-spacing: 0.1em;
    color: orange;
  }
}
</style>
<h3 class="springy-text">Animations!</h3>

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CSS Specifications

Browser Support

The following table provided by Caniuse.com shows the level of browser support for this feature.

Vendor Prefixes

For maximum browser compatibility many web developers add browser-specific properties by using extensions such as -webkit- for Safari, Google Chrome, and Opera (newer versions), -ms- for Internet Explorer, -moz- for Firefox, -o- for older versions of Opera etc. As with any CSS property, if a browser doesn't support a proprietary extension, it will simply ignore it.

This practice is not recommended by the W3C, however in many cases, the only way you can test a property is to include the CSS extension that is compatible with your browser.

The major browser manufacturers generally strive to adhere to the W3C specifications, and when they support a non-prefixed property, they typically remove the prefixed version. Also, W3C advises vendors to remove their prefixes for properties that reach Candidate Recommendation status.

Many developers use Autoprefixer, which is a postprocessor for CSS. Autoprefixer automatically adds vendor prefixes to your CSS so that you don't need to. It also removes old, unnecessary prefixes from your CSS.

You can also use Autoprefixer with preprocessors such as Less and Sass.