resize event not triggered on div

Take a look at this example:

I've attached a resize event listener on container div. After opening up dev tools, and modifying the width of container, resize callback does not get called. What am I missing?

PS: I am not interested in window resize event, only in container div.

var container = document.getElementsByClassName("container")[0];
container.addEventListener("resize", function() {
<div class="container"></div>


  • resize is only valid for the window. If supported you can use ResizeObserver.

    new ResizeObserver(() => console.log("resizing")).observe(container);

    Otherwise, you will probably have to poll using setInterval and check the size.