CSS animation

The CSS animation property is a shorthand property for setting multiple animation properties in one place.

To create an animation using CSS, use the animation property in conjunction with the @keyframes keyword/at-rule, which allows you to define visual effects for your animation.

The CSS animation property is a time-efficient way of coding your CSS animations. It allows you to set values for the following properties: animation-name, animation-duration, animation-timing-function, animation-delay, animation-iteration-count, animation-direction, and animation-fill-mode.

Syntax

Here's the official syntax for this property.

animation: [<animation-name> || <animation-duration> || <animation-timing-function> || <animation-delay> || <animation-iteration-count> || <animation-direction> || <animation-fill-mode>] [, [<animation-name> || <animation-duration> || <animation-timing-function> || <animation-delay> || <animation-iteration-count> || <animation-direction> || <animation-fill-mode>] ]

Note that order is important within each animation definition. In particular, the first "time" value is treated as animation-duration, and the second is treated as animation-delay.

Possible Values

Here's a brief explanation of the possible values.

animation-name
The name of the animation.
animation-duration
Defines the length of time that an animation takes to complete one iteration.
animation-timing-function
Specifies how an animation progresses between keyframes.
animation-delay
Defines when an animation starts.
animation-iteration-count
Specifies the number of times an animation iterates.
animation-direction
Determines whether the animation should play in reverse on alternate iterations.
animation-fill-mode
Allows you to define what values are applied by the animation outside the time it is executing.

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
See individual properties
Applies To
All elements, and the :before and :after pseudo elements
Inherited?
No
Media
Visual

Example Code

Basic CSS

animation: bounce 1s ease-in 2s 6 alternate none;

This is the shorthand equivalent to:

animation-name: bounce;
animation-duration: 1s;
animation-timing-function: ease-in;
animation-delay: 2s;
animation-iteration-count: 6;
animation-direction: alternate;
animation-fill-mode: none;

Working Example within an HTML Document

<!DOCTYPE html>
<title>Example</title>
<style>
div.bounce {
  width: 100px;
  padding: 20px;
  background: gold;
  position: relative;
  animation: bounce 1s ease-in 2s 6 alternate none;
}
@keyframes bounce {
	from {
	  top: 0px;
	  left: 0px;
	  }
	to {
	  top: 150px;
	  left: 150px;
	}
}
</style>
<div class="bounce">Bouncing box...</div>

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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.