Is there anyway to animate an ellipsis with CSS animations?

How about a slightly modified version of @xec's answer: http://codepen.io/thetallweeks/pen/yybGra

HTML

A single class added to the element:

<div class="loading">Loading</div>

CSS

Animation that uses steps. See MDN docs

.loading:after {
  overflow: hidden;
  display: inline-block;
  vertical-align: bottom;
  -webkit-animation: ellipsis steps(4,end) 900ms infinite;      
  animation: ellipsis steps(4,end) 900ms infinite;
  content: "\2026"; /* ascii code for the ellipsis character */
  width: 0px;
}

@keyframes ellipsis {
  to {
    width: 20px;    
  }
}

@-webkit-keyframes ellipsis {
  to {
    width: 20px;    
  }
}

@xec's answer has more of a slide-in effect on the dots, while this allows the dots to appear instantly.

You could try to use the animation-delay property and time each ellipsis character. In this case I've put each ellipsis character in a <span class> so I can animate them separately.

I made a demo, which isn't perfect, but it shows at least what I mean :)

The code from my example:

HTML

Loading<span class="one">.</span><span class="two">.</span><span class="three">.</span>​

CSS

.one {
    opacity: 0;
    -webkit-animation: dot 1.3s infinite;
    -webkit-animation-delay: 0.0s;
    animation: dot 1.3s infinite;
    animation-delay: 0.0s;
}

.two {
    opacity: 0;
    -webkit-animation: dot 1.3s infinite;
    -webkit-animation-delay: 0.2s;
    animation: dot 1.3s infinite;
    animation-delay: 0.2s;
}

.three {
    opacity: 0;
    -webkit-animation: dot 1.3s infinite;
    -webkit-animation-delay: 0.3s;
    animation: dot 1.3s infinite;
    animation-delay: 0.3s;
}

@-webkit-keyframes dot {
    0% {
        opacity: 0;
    }
    50% {
        opacity: 0;
    }
    100% {
        opacity: 1;
    }
}

@keyframes dot {
    0% {
        opacity: 0;
    }
    50% {
        opacity: 0;
    }
    100% {
        opacity: 1;
    }
}

Even a more simple solution, works pretty well!

<style>
    .loading:after {
      display: inline-block;
      animation: dotty steps(1,end) 1s infinite;
      content: '';
    }

    @keyframes dotty {
        0%   { content: ''; }
        25%  { content: '.'; }
        50%  { content: '..'; }
        75%  { content: '...'; }
        100% { content: ''; }
    }
</style>
<div class="loading">Loading</div>

Just edited the content with animation instead of hiding some dots...

Demo here: https://jsfiddle.net/f6vhway2/1/

---

Edit: Thanks to @BradCollins for pointing out that content is not an animatable property.

https://www.w3.org/TR/css3-transitions/#animatable-css

So this is a WebKit/Blink/Electron only solution. (But it works in current FF versions as well)