CSS

Animations

CSS Animations

CSS allows animation of HTML elements without using JavaScript or Flash!

CSS

In this chapter you will learn about the following properties:

• @keyframes
• animation-name
• animation-duration
• animation-delay
• animation-iteration-count
• animation-direction
• animation-timing-function
• animation-fill-mode
• animation

Browser Support for Animations

The numbers in the table specify the first browser version that fully supports the property.

Property

@keyframes
43.0
10.0
16.0
9.0
30.0

animation-name
43.0
10.0
16.0
9.0
30.0

animation-duration
43.0
10.0
16.0
9.0
30.0

animation-delay
43.0
10.0
16.0
9.0
30.0

animation-iteration-count
43.0
10.0
16.0
9.0
30.0

animation-direction
43.0
10.0
16.0
9.0
30.0

animation-timing-function
43.0
10.0
16.0
9.0
30.0

animation-fill-mode
43.0
10.0
16.0
9.0
30.0

animation
43.0
10.0
16.0
9.0
30.0

What are CSS Animations?

An animation lets an element gradually change from one style to another.

You can change as many CSS properties you want, as many times as you want.

To use CSS animation, you must first specify some keyframes for the
animation.

Keyframes hold what styles the element will have at certain times.

The @keyframes Rule

When you specify CSS styles inside the @keyframes
rule, the animation will gradually change from the current style to the new style
at certain times.

To get an animation to work, you must bind the animation to an element.

The following example binds the “example” animation to the <div> element.
The animation will last for 4 seconds, and it will gradually change the
background-color of the <div> element from “red” to “yellow”:

Example

/* The animation code */
@keyframes example {
  from {background-color: red;}
 
to {background-color: yellow;}
}

/* The element to apply the animation to */
div {
  width: 100px;
  height: 100px;
 
background-color: red;
 
animation-name: example;
  animation-duration: 4s;
}

Try it Yourself »

Note: The animation-duration property
defines how long an animation should take to complete. If the animation-duration property is not specified,
no animation will occur, because
the default value is 0s (0 seconds). 

In the example above we have specified when the style will change by using
the keywords “from” and “to” (which represents 0% (start) and 100% (complete)).

It is also possible to use percent. By using percent, you can add as many
style changes as you like.

The following example will change the background-color of the <div>
element when the animation is 25% complete, 50% complete, and again when the animation is 100% complete:

Example

/* The animation code */
@keyframes example
{
  0%   {background-color: red;}
 
25%  {background-color: yellow;}
  50%  {background-color: blue;}
  100% {background-color: green;}
}

/* The element to apply the animation to */
div {
 
width: 100px;
  height: 100px;
  background-color: red;
  animation-name: example;
  animation-duration: 4s;
}

Try it Yourself »

The following example will change both the background-color and the position of the <div>
element when the animation is 25% complete, 50% complete, and again when the animation is 100% complete:

Example

/* The animation code */
@keyframes example
{
  0%   {background-color:red; left:0px; top:0px;}
 
25%  {background-color:yellow; left:200px; top:0px;}
 
50%  {background-color:blue; left:200px; top:200px;}
 
75%  {background-color:green; left:0px; top:200px;}
 
100% {background-color:red; left:0px; top:0px;}
}

/* The element to apply the animation to */
div {
 
width: 100px;
  height: 100px;
 
position: relative;
  background-color: red;
  animation-name: example;
  animation-duration: 4s;
}

Try it Yourself »

Delay an Animation

The animation-delay property specifies a delay for the start of an animation.

The following example has a 2 seconds delay before starting the animation:

Example

div {
 
width: 100px;
  height: 100px;
 
position: relative;
  background-color: red;
  animation-name: example;
 
animation-duration: 4s;
  animation-delay: 2s;
}

Try it Yourself »

Negative values are also allowed. If using negative values, the animation
will start as if it had already been playing for N seconds.

In the following example, the animation will start as if it had already been
playing for 2 seconds:

Example

div {
 
width: 100px;
  height: 100px;
 
position: relative;
  background-color: red;
 
animation-name: example;
 
animation-duration: 4s;
  animation-delay: -2s;
}

Try it Yourself »

Set How Many Times an Animation Should Run

The animation-iteration-count property specifies the number of times an animation should run.

The following example will run the animation 3 times before it stops:

Example

div {
  width: 100px;
  height: 100px;
  position: relative;
  background-color: red;
  animation-name: example;
  animation-duration: 4s;
  animation-iteration-count: 3;
}

Try it Yourself »

The following example uses the value “infinite” to make the animation
continue for ever:

Example

div {
 
width: 100px;
  height: 100px;
 
position: relative;
  background-color: red;
  animation-name: example;
  animation-duration: 4s;
  animation-iteration-count:
infinite;
}

Try it Yourself »

Run Animation in Reverse Direction or Alternate Cycles

The animation-direction property specifies
whether an animation should be played forwards, backwards or in alternate
cycles.

The animation-direction property can have the following values:

• normal – The animation is played as normal
  (forwards). This is default
• reverse – The animation is played in
  reverse direction (backwards)
• alternate – The animation is played
  forwards first, then backwards
• alternate-reverse – The animation is played
  backwards first, then forwards

The following example will run the animation in reverse direction (backwards):

Example

div {
 
width: 100px;
  height: 100px;
 
position: relative;
  background-color: red;
 
animation-name: example;
 
animation-duration: 4s;
  animation-direction:
reverse;
}

Try it Yourself »

The following example uses the value “alternate” to make the animation
run forwards first, then backwards:

Example

div {
 
width: 100px;
  height: 100px;
 
position: relative;
  background-color: red;
  animation-name: example;
  animation-duration: 4s;
  animation-iteration-count: 2;
  animation-direction:
alternate;
}

Try it Yourself »

The following example uses the value “alternate-reverse” to make the animation
run backwards first, then forwards:

Example

div {
  width: 100px;
  height: 100px;
 
position: relative;
  background-color: red;
  animation-name: example;
  animation-duration: 4s;
  animation-iteration-count: 2;
  animation-direction:
alternate-reverse;
}

Try it Yourself »

Specify the Speed Curve of the Animation

The animation-timing-function property specifies the speed curve of the
animation.

The animation-timing-function property can have the following values:

• ease – Specifies an animation with a slow start, then fast, then end slowly (this is default)
• linear – Specifies an animation with the same speed from start to end
• ease-in – Specifies an animation with a slow start
• ease-out – Specifies an animation with a slow end
• ease-in-out – Specifies an animation with a slow start and end
• cubic-bezier(n,n,n,n) – Lets you define your own values in a cubic-bezier function

The following example shows some of the different speed curves that can be used:

Specify the fill-mode For an Animation

CSS animations do not affect an element before the first keyframe is played
or after the last keyframe is played. The animation-fill-mode property can
override this behavior.

The animation-fill-mode property specifies a
style for the target element when the animation is not playing (before it
starts, after it ends, or both).

The animation-fill-mode property can have the following values:

• none – Default value. Animation will not
  apply any styles to the element before or after it is executing
• forwards – The element will retain the
  style values that is set by the last keyframe (depends on animation-direction
  and animation-iteration-count)
• backwards – The element will get the style
  values that is set by the first keyframe (depends on animation-direction), and
  retain this during the animation-delay period
• both – The animation will follow the rules
  for both forwards and backwards, extending the animation properties in both
  directions

The following example lets the <div> element retain the style values from the
last keyframe when the animation ends:

Example

div {
  width: 100px;
  height: 100px;
  background: red;
  position: relative;
  animation-name: example;
  animation-duration: 3s;
  animation-fill-mode: forwards;
}

Try it Yourself »

The following example lets the <div> element get the style values set by the
first keyframe before the animation starts (during the animation-delay period):

Example

div {
  width: 100px;
  height: 100px;
 
background: red;
  position: relative;
 
animation-name: example;
 
animation-duration: 3s;
 
animation-delay: 2s;
  animation-fill-mode: backwards;
}

Try it Yourself »

The following example lets the <div> element get the style values set
by the first keyframe before the animation starts, and retain the style values
from the last keyframe when the animation ends:

Example

div {
  width: 100px;
  height: 100px;
  background: red;
  position: relative;
 
animation-name: example;
 
animation-duration: 3s;
 
animation-delay: 2s;
  animation-fill-mode: both;
}

Try it Yourself »

Animation Shorthand Property

The example below uses six of the animation properties:

Example

div
{
 
animation-name: example;
 
animation-duration: 5s;
 
animation-timing-function: linear;
 
animation-delay: 2s;
 
animation-iteration-count: infinite;
 
animation-direction: alternate;
}

Try it Yourself »

The same animation effect as above can be achieved by using the shorthand
animation property:

Example

div
{
  animation: example 5s linear 2s infinite alternate;
}

Try it Yourself »

Test Yourself With Exercises

Exercise:

Add a 2 second animation for the <div> element, which changes the color from red to blue. Call the animation “example”.

<style>
div {
  width: 100px;
  height: 100px;
  background-color: red;
  animation-name: ;
  : 2s;
}

@keyframes example {
  from {: red;}
  to {: blue;}
}
</style>

<body>
  <div>This is a div</div>
</body>

Start the Exercise

CSS Animation Properties

The following table lists the @keyframes rule and all the CSS animation properties:

Property
Description

@keyframes
Specifies the animation code

animation
A shorthand property for setting all the animation properties

animation-delay
Specifies a delay for the start of an animation

animation-direction
Specifies whether an animation should be played forwards, backwards or
in alternate cycles

animation-duration
Specifies how long time an animation should take to complete one cycle

animation-fill-mode
Specifies a style for the element when the animation is not playing
(before it starts, after it ends, or both)

animation-iteration-count
Specifies the number of times an animation should be played

animation-name
Specifies the name of the @keyframes animation

animation-play-state
Specifies whether the animation is running or paused

animation-timing-function
Specifies the speed curve of the animation