The @keyframes
CSS at-rule controls the intermediate steps in a CSS animation sequence by defining styles for keyframes (or waypoints) along the animation sequence. This gives more control over the intermediate steps of the animation sequence than transitions.
@keyframes slidein { from { margin-left: 100%; width: 300%; } to { margin-left: 0%; width: 100%; } }
JavaScript can access the @keyframes
at-rule with the CSS object model interface CSSKeyframesRule
.
To use keyframes, create a @keyframes
rule with a name that is then used by the animation-name
property to match an animation to its keyframe declaration. Each @keyframes
rule contains a style list of keyframe selectors, which specify percentages along the animation when the keyframe occurs, and a block containing the styles for that keyframe.
You can list the keyframe percentages in any order; they will be handled in the order they should occur.
If a keyframe rule doesn't specify the start or end states of the animation (that is, 0%
/from
and 100%
/to
, browsers will use the element's existing styles for the start/end states. This can be used to animate an element from its initial state and back.
Properties that can't be animated in keyframe rules are ignored, but supported properties will still be animated.
If multiple keyframe sets exist for a given name, the last one encountered by the parser is used. @keyframes
rules don't cascade, so animations never derive keyframes from more than one rule set.
If a given animation time offset is duplicated, the last keyframe in the @keyframes
rule for that percentage is used for that frame. There's no cascading within a @keyframes
rule if multiple keyframes specify the same percentage values.
Properties that aren't specified in every keyframe are interpolated if possible — properties that can't be interpolated are dropped from the animation. For example:
@keyframes identifier { 0% { top: 0; left: 0; } 30% { top: 50px; } 68%, 72% { left: 50px; } 100% { top: 100px; left: 100%; } }
Here, the top
property animates using the 0%
, 30%
, and 100%
keyframes, and left
animates using the 0%
, 68%
, and 100%
keyframes.
If a keyframe is defined multiple times but not all affected properties are in each keyframe, only the values specified in the latest keyframe are considered. For example:
@keyframes identifier { 0% { top: 0; } 50% { top: 30px; left: 20px; } 50% { top: 10px; } 100% { top: 0; } }
In this example, at the 50%
keyframe, the value used is top: 10px
and all other values at this keyframe are ignored.
Cascading keyframes are supported starting in Firefox 14. For the example above, it means that at the 50%
keyframe, the value left: 20px
will be considered. This is not defined in the specification yet, but it is being discussed.
!important
in a keyframeDeclarations in a keyframe qualified with !important
are ignored.
@keyframes important1 { from { margin-top: 50px; } 50% { margin-top: 150px !important; } /* ignored */ to { margin-top: 100px; } } @keyframes important2 { from { margin-top: 50px; margin-bottom: 100px; } to { margin-top: 150px !important; /* ignored */ margin-bottom: 50px; } }
<custom-ident>
from
0%
.to
100%
.<percentage>
@keyframes <keyframes-name> { <keyframe-block-list> }where
<keyframes-name> = <custom-ident> | <string>
<keyframe-block-list> = <keyframe-block>+where
<keyframe-block> = <keyframe-selector># { <declaration-list> }where
<keyframe-selector> = from | to | <percentage>
See Using CSS animations for examples.
Specification | Status | Comment |
---|---|---|
CSS Animations The definition of '@keyframes' in that specification. | Working Draft |
Desktop | ||||||
---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
Basic support | 43
|
Yes | 16
|
10 | 12.1 — 15
|
9
|
Ignore !important declarations |
? | ? | 19 | ? | ? | ? |
Mobile | |||||||
---|---|---|---|---|---|---|---|
Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
Basic support | 43
|
43
|
Yes | 16
|
12.1
|
Yes
|
4.0
|
Ignore !important declarations |
? | ? | ? | 19 | ? | ? | ? |
@keyframes
unsupported in scoped stylesheets in Firefox (bug 830056).
© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/CSS/@keyframes