files/en-us/web/api/element/animationiteration_event/index.md
{{APIRef("Web Animations")}}
The animationiteration event is fired when an iteration of a CSS Animation ends, and another one begins. This event does not occur at the same time as the {{domxref("Element/animationend_event", "animationend")}} event, and therefore does not occur for animations with an animation-iteration-count of one.
Use the event name in methods like {{domxref("EventTarget.addEventListener", "addEventListener()")}}, or set an event handler property.
addEventListener("animationiteration", (event) => { })
onanimationiteration = (event) => { }
An {{domxref("AnimationEvent")}}. Inherits from {{domxref("Event")}}.
{{InheritanceDiagram("AnimationEvent")}}
Also inherits properties from its parent {{domxref("Event")}}.
float giving the amount of time the animation has been running, in seconds, when this event fired, excluding any time the animation was paused. For an animationstart event, elapsedTime is 0.0 unless there was a negative value for {{cssxref("animation-delay")}}, in which case the event will be fired with elapsedTime containing (-1 * delay).'::', containing the name of the pseudo-element the animation runs on. If the animation doesn't run on a pseudo-element but on the element, an empty string: ''.This code uses animationiteration to keep track of the number of iterations an animation has completed:
const animated = document.querySelector(".animated");
let iterationCount = 0;
animated.addEventListener("animationiteration", () => {
iterationCount++;
console.log(`Animation iteration count: ${iterationCount}`);
});
The same, but using the onanimationiteration event handler property:
const animated = document.querySelector(".animated");
let iterationCount = 0;
animated.onanimationiteration = () => {
iterationCount++;
console.log(`Animation iteration count: ${iterationCount}`);
};
<div class="animation-example">
<div class="container">
<p class="animation">You chose a cold night to visit our planet.</p>
</div>
<button class="activate" type="button">Activate animation</button>
<div class="event-log"></div>
</div>
.container {
height: 3rem;
}
.event-log {
width: 25rem;
height: 2rem;
border: 1px solid black;
margin: 0.2rem;
padding: 0.2rem;
}
.animation.active {
animation-duration: 2s;
animation-name: slide-in;
animation-iteration-count: 2;
}
@keyframes slide-in {
from {
transform: translateX(100%) scaleX(3);
}
to {
transform: translateX(0) scaleX(1);
}
}
const animation = document.querySelector("p.animation");
const animationEventLog = document.querySelector(
".animation-example>.event-log",
);
const applyAnimation = document.querySelector(
".animation-example>button.activate",
);
let iterationCount = 0;
animation.addEventListener("animationstart", () => {
animationEventLog.textContent = `${animationEventLog.textContent}'animation started' `;
});
animation.addEventListener("animationiteration", () => {
iterationCount++;
animationEventLog.textContent = `${animationEventLog.textContent}'animation iterations: ${iterationCount}' `;
});
animation.addEventListener("animationend", () => {
animationEventLog.textContent = `${animationEventLog.textContent}'animation ended'`;
animation.classList.remove("active");
applyAnimation.textContent = "Activate animation";
});
animation.addEventListener("animationcancel", () => {
animationEventLog.textContent = `${animationEventLog.textContent}'animation canceled'`;
});
applyAnimation.addEventListener("click", () => {
animation.classList.toggle("active");
animationEventLog.textContent = "";
iterationCount = 0;
const active = animation.classList.contains("active");
applyAnimation.textContent = active
? "Cancel animation"
: "Activate animation";
});
{{ EmbedLiveSample('Live_example', '100%', '150px') }}
{{Specifications}}
{{Compat}}