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animation

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The animation property in CSS can be used to animate many other CSS properties such as color, background-color, height, or width. Each animation needs to be defined with the @keyframes at-rule which is then called with the animation property, like so:

.element {
  animation: pulse 5s infinite;
}

@keyframes pulse {
  0% {
    background-color: #001F3F;
  }
  100% {
    background-color: #FF4136;
  }
}

See the Pen A simple animation by CSS-Tricks (@css-tricks) on CodePen.

Each @keyframes at-rule defines what should happen at specific moments during the animation. For example, 0% is the beginning of the animation and 100% is the end. These keyframes can then be controlled either by the shorthand animation property, or its eight sub-properties, to give more control over how those keyframes should be manipulated.

Sub-properties

  • animation-name: declares the name of the @keyframes at-rule to manipulate.
  • animation-duration: the length of time it takes for an animation to complete one cycle.
  • animation-timing-function: establishes preset acceleration curves such as ease or linear.
  • animation-delay: the time between the element being loaded and the start of the animation sequence.
  • animation-direction: sets the direction of the animation after the cycle. Its default resets on each cycle.
  • animation-iteration-count: the number of times the animation should be performed.
  • animation-fill-mode: sets which values are applied before/after the animation.
    For example, you can set the last state of the animation to remain on screen, or you can set it to switch back to before when the animation began.
  • animation-play-state: pause/play the animation.

These sub-properties can then be used like so:

@keyframes stretch {
  /* declare animation actions here */
}

.element {
  animation-name: stretch;
  animation-duration: 1.5s; 
  animation-timing-function: ease-out; 
  animation-delay: 0;
  animation-direction: alternate;
  animation-iteration-count: infinite;
  animation-fill-mode: none;
  animation-play-state: running; 
}

/*
  is the same as:
*/

.element {
  animation: 
    stretch
    1.5s
    ease-out
    0
    alternate
    infinite
    none
    running;
}

See the Pen EjaJNd by CSS-Tricks (@css-tricks) on CodePen.

Here's a full list of which values each of these sub-properties can take:

animation-timing-function ease, ease-out, ease-in, ease-in-out, linear, cubic-bezier(x1, y1, x2, y2) (e.g. cubic-bezier(0.5, 0.2, 0.3, 1.0))
animation-duration Xs or Xms
animation-delay Xs or Xms
animation-iteration-count X
animation-fill-mode forwards, backwards, both, none
animation-direction normal, alternate
animation-play-state paused, running, running

Multiple steps

If an animation has the same starting and ending properties, it's useful to comma-separate the 0% and 100% values inside @keyframes:

@keyframes pulse {
  0%, 100% {
    background-color: yellow;
  }
  50% {
    background-color: red;
  }
}

Multiple animations

You can comma-separate the values to declare multiple animations on a selector as well. In the example below, we want to change the color of the circle in a @keyframe whilst also nudging it from side to side with another.

.element {
  animation: 
    pulse 3s ease infinite alternate, 
    nudge 5s linear infinite alternate;
}

See the Pen c6d27fda8e1244d44bf04728049d7c1d by CSS-Tricks (@css-tricks) on CodePen.

Performance

Animating most properties is a performance concern, so we should proceed with caution before animating any property. However, there are certain combinations that can be animated safely:

  • transform: translate()
  • transform: scale()
  • transform: rotate()
  • opacity

Which properties can be animated?

MDN has a list of CSS properties which can be animated. Animatable properties tend to colors and numbers. An example a non-animatable property is background-image.

More information

Browser support

Chrome Safari Firefox Opera IE Android iOS
6+ 5+ 5+ 12+ 10+ 4.4+ 4+

Prefixes

Although browser support is quite good for this property in modern browsers, we might want to support as many older browsers as we can. In that case we'd need to use vendor prefixes:

.element {
  -webkit-animation: KEYFRAME-NAME 5s infinite;
  -moz-animation:    KEYFRAME-NAME 5s infinite;
  -o-animation:      KEYFRAME-NAME 5s infinite;
  animation:         KEYFRAME-NAME 5s infinite;
}

@-webkit-keyframes KEYFRAME-NAME {
  0%   { opacity: 0; }
  100% { opacity: 1; }
}
@-moz-keyframes KEYFRAME-NAME {
  0%   { opacity: 0; }
  100% { opacity: 1; }
}
@-o-keyframes KEYFRAME-NAME {
  0%   { opacity: 0; }
  100% { opacity: 1; }
}
@keyframes KEYFRAME-NAME {
  0%   { opacity: 0; }
  100% { opacity: 1; }
}

Comments

  1. almundzir
    Permalink to comment#

    THIS IS SO COOL THANKS

  2. Dan
    Permalink to comment#

    Nice

  3. egasimus

    Hey,

    as far as I know, Opera has also implemented animations using the -o- -prefix. Maybe this calls for an update?

    Also, using the -webkit- prefix in your examples could possibly promote the bad practice of using -webkit- only. Maybe such examples need to be changed to the prefix-free version instead?

    Best regards,
    Adam Avramov

  4. Xiaopeng
    Permalink to comment#

    They are definitely great and better than other tutorials! Thanks, Chris!

  5. Lukas
    Permalink to comment#

    Hi Chris,
    I’m not sure if you’re aware, but @-ms-keyframes has never existed. IE10+ supports the @keyframes property, and < IE9 doesn’t support animation at all.

    • Chris Coyier
      Permalink to comment#

      I did know that, this was way out of date that way (pre me knowing that I guess). Got it fixed up.

  6. manjit
    Permalink to comment#

    hello sir,
    I want to run animation form{left:0}to{left:75px} then i want to stop my content at place left:75px; permanently until i move my mouse out. Is this possible???if yes then how?????? Please help

  7. Alex Safayan
    Permalink to comment#

    I was wondering if there is other options instead of ‘alternate’. Please help!

    Alex Safayan

  8. Baraza
    Permalink to comment#

    This teachings on animations are amaizing!!

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