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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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:
Example
#div1 {animation-timing-function: linear;}
#div2 {animation-timing-function: ease;}
#div3 {animation-timing-function: ease-in;}
#div4 {animation-timing-function: ease-out;}
#div5 {animation-timing-function: ease-in-out;}
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;
}
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;
}
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;
}
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;
}
The same animation effect
as above can be achieved by using the shorthand animation property:
Example
div {
animation: example 5s linear 2s infinite alternate;
}
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 |
