Element: transitionend event

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener("transitionend", (event) => {});

ontransitionend = (event) => {};

A TransitionEvent. Inherits from Event.

Also inherits properties from its parent Event.

TransitionEvent.propertyName Read only

A string containing the name CSS property associated with the transition.

TransitionEvent.elapsedTime Read only

A float giving the amount of time the transition has been running, in seconds, when this event fired. This value is not affected by the transition-delay property.

TransitionEvent.pseudoElement Read only

A string, starting with ::, containing the name of the pseudo-element the animation runs on. If the transition doesn't run on a pseudo-element but on the element, an empty string: ''.

This code gets an element that has a transition defined and adds a listener to the transitionend event:

const transition = document.querySelector(".transition");

transition.addEventListener("transitionend", () => {
  console.log("Transition ended");
});

The same, but using ontransitionend:

const transition = document.querySelector(".transition");

transition.ontransitionend = () => {
  console.log("Transition ended");
};

In the following example, we have a simple <div> element, styled with a transition that includes a delay:

<div class="transition">Hover over me</div>
<div class="message"></div>

.transition {
  width: 100px;
  height: 100px;
  background: rgb(255 0 0 / 100%);
  transition-property: transform, background;
  transition-duration: 2s;
  transition-delay: 1s;
}

.transition:hover {
  transform: rotate(90deg);
  background: rgb(255 0 0 / 0%);
}

To this, we'll add some JavaScript to indicate that the transitionstart, transitionrun, transitioncancel and transitionend events fire. In this example, to cancel the transition, stop hovering over the transitioning box before the transition ends. For the transition end event to fire, stay hovered over the transition until the transition ends.

const message = document.querySelector(".message");
const el = document.querySelector(".transition");

el.addEventListener("transitionrun", () => {
  message.textContent = "transitionrun fired";
});

el.addEventListener("transitionstart", () => {
  message.textContent = "transitionstart fired";
});

el.addEventListener("transitioncancel", () => {
  message.textContent = "transitioncancel fired";
});

el.addEventListener("transitionend", () => {
  message.textContent = "transitionend fired";
});

The transitionend event is fired in both directions: when the box finishes turning and the opacity hits 0 or 1, depending on the direction.

If there is no transition delay or duration, if both are 0s or neither is declared, there is no transition, and none of the transition events are fired.

If the transitioncancel event is fired, the transitionend event will not fire.

• The TransitionEvent interface
• CSS properties: transition, transition-delay, transition-duration, transition-property, transition-timing-function
• Related events: transitionrun, transitionstart, transitioncancel