Inténtalo tú mismo - JavaScript Reference animationstart

<!DOCTYPE html>
<html>
<head>
<style> 
#myDIV {
    margin: 25px;
    width: 550px;
    height: 100px;
    background: orange;
    position: relative;
    font-size: 20px;
}

/* Chrome, Safari, Opera */
@-webkit-keyframes mymove {
    from {top: 0px;}
    to {top: 200px;}
}

@keyframes mymove {
    from {top: 0px;}
    to {top: 200px;}
}
</style>
</head>
<body>

<p>This example uses the addEventListener() method to attach an "animationstart", "animationiteration" and "animationend" event to a DIV element.</p>

<div id="myDIV" onclick="myFunction()">Click me to start the animation.</div>

// Start the animation with JavaScript
function myFunction() {
    x.style.WebkitAnimation = "mymove 4s 2"; // Code for Chrome, Safari and Opera
    x.style.animation = "mymove 4s 2";       // Standard syntax
}

// Code for Chrome, Safari and Opera
x.addEventListener("webkitAnimationStart", myStartFunction);
x.addEventListener("webkitAnimationIteration", myRepeatFunction);
x.addEventListener("webkitAnimationEnd", myEndFunction);

// Standard syntax
x.addEventListener("animationstart", myStartFunction);
x.addEventListener("animationiteration", myRepeatFunction);
x.addEventListener("animationend", myEndFunction);

function myStartFunction() {
    this.innerHTML = "animationstart event occured - The animation has started";
    this.style.backgroundColor = "pink";
}

function myRepeatFunction() {
    this.innerHTML = "animationiteration event occured - The animation was played again";
    this.style.backgroundColor = "lightblue";
}

function myEndFunction() {
    this.innerHTML = "animationend event occured - The animation has completed";
    this.style.backgroundColor = "lightgray";
}
</script>

</body>
</html>