CSS smooth bounce animation

Question

I needed to implement infinite bounce effect using pure CSS, so I referred this site and ended up doing this .

 .animated { -webkit-animation-duration: 2.5s; animation-duration: 2.5s; -webkit-animation-fill-mode: both; animation-fill-mode: both; -webkit-animation-timing-function: linear; animation-timing-function: linear; animation-iteration-count: infinite; -webkit-animation-iteration-count: infinite; } @-webkit-keyframes bounce { 0%, 20%, 40%, 60%, 80%, 100% {-webkit-transform: translateY(0);} 50% {-webkit-transform: translateY(-5px);} } @keyframes bounce { 0%, 20%, 40%, 60%, 80%, 100% {transform: translateY(0);} 50% {transform: translateY(-5px);} } .bounce { -webkit-animation-name: bounce; animation-name: bounce; } #animated-example { width: 20px; height: 20px; background-color: red; position: relative; top: 100px; left: 100px; border-radius: 50%; } hr { position: relative; top: 92px; left: -300px; width: 200px; } 

 <div id="animated-example" class="animated bounce"></div> <hr> 

Now, my only problem is the bouncing element takes a longer rest before it starts bouncing again. How can I make it bounce smoothly just like the bounce effect we get by using jQuery.animate ?

Answer 1

The long rest in between is due to your keyframe settings. Your current keyframe rules mean that the actual bounce happens only between 40% - 60% of the animation duration (that is, between 1s - 1.5s mark of the animation). Remove those rules and maybe even reduce the animation-duration to suit your needs.

 .animated { -webkit-animation-duration: .5s; animation-duration: .5s; -webkit-animation-fill-mode: both; animation-fill-mode: both; -webkit-animation-timing-function: linear; animation-timing-function: linear; animation-iteration-count: infinite; -webkit-animation-iteration-count: infinite; } @-webkit-keyframes bounce { 0%, 100% { -webkit-transform: translateY(0); } 50% { -webkit-transform: translateY(-5px); } } @keyframes bounce { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-5px); } } .bounce { -webkit-animation-name: bounce; animation-name: bounce; } #animated-example { width: 20px; height: 20px; background-color: red; position: relative; top: 100px; left: 100px; border-radius: 50%; } hr { position: relative; top: 92px; left: -300px; width: 200px; } 

 <div id="animated-example" class="animated bounce"></div> <hr> 

---

Here is how your original keyframe settings would be interpreted by the browser:

• At 0% (that is, at 0s or start of animation) - translate by 0px in Y axis.
• At 20% (that is, at 0.5s of animation) - translate by 0px in Y axis.
• At 40% (that is, at 1s of animation) - translate by 0px in Y axis.
• At 50% (that is, at 1.25s of animation) - translate by 5px in Y axis. This results in a gradual upward movement.
• At 60% (that is, at 1.5s of animation) - translate by 0px in Y axis. This results in a gradual downward movement.
• At 80% (that is, at 2s of animation) - translate by 0px in Y axis.
• At 100% (that is, at 2.5s or end of animation) - translate by 0px in Y axis.

Answer 2

Here is code not using the percentage in the keyframes. Because you used percentages the animation does nothing a long time.

• 0% translate 0px
• 20% translate 0px
• etc.

How does this example work:

1. We set an animation . This is a short hand for animation properties.
2. We immediately start the animation since we use from and to in the keyframes. from is = 0% and to is = 100%
3. We can now control how fast it will bounce by setting the animation time: animation: bounce 1s infinite alternate; the 1s is how long the animation will last.

 .ball { margin-top: 50px; border-radius: 50%; width: 50px; height: 50px; background-color: cornflowerblue; border: 2px solid #999; animation: bounce 1s infinite alternate; -webkit-animation: bounce 1s infinite alternate; } @keyframes bounce { from { transform: translateY(0px); } to { transform: translateY(-15px); } } @-webkit-keyframes bounce { from { transform: translateY(0px); } to { transform: translateY(-15px); } } 

 <div class="ball"></div> 

Answer 3

In case you're already using the transform property for positioning your element (as I currently am), you can also animate the top margin:

.ball {
  animation: bounce 1s infinite alternate;
  -webkit-animation: bounce 1s infinite alternate;
}

@keyframes bounce {
  from {
    margin-top: 0;
  }
  to {
    margin-top: -15px;
  }
}