Web/API/Element/scroll event

The scroll event fires an element has been scrolled.

Bubbles	No
Cancelable	No
Interface	`Event`
Event handler property	`onscroll`

Note: In iOS UIWebViews, scroll events are not fired while scrolling is taking place; they are only fired after the scrolling has completed. See Bootstrap issue #16202. Safari and WKWebViews are not affected by this bug.

Examples

Scroll event throttling

Since scroll events can fire at a high rate, the event handler shouldn't execute computationally expensive operations such as DOM modifications. Instead, it is recommended to throttle the event using requestAnimationFrame(), setTimeout(), or a CustomEvent, as follows.

Note, however, that input events and animation frames are fired at about the same rate, and therefore the optimization below is often unnecessary. This example optimizes the scroll event for requestAnimationFrame.

// Reference: http://www.html5rocks.com/en/tutorials/speed/animations/

let last_known_scroll_position = 0;
let ticking = false;

function doSomething(scroll_pos) {
  // Do something with the scroll position
}

window.addEventListener('scroll', function(e) {
  last_known_scroll_position = window.scrollY;

  if (!ticking) {
    window.requestAnimationFrame(function() {
      doSomething(last_known_scroll_position);
      ticking = false;
    });

    ticking = true;
  }
});

Note: You can find more examples on the resize event page.

Specifications

Specification	Status
CSS Object Model (CSSOM) View Module	Working Draft

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`scroll` event	Chrome Full support Yes	Edge Full support ≤18	Firefox Full support Yes	IE ?	Opera ?	Safari ?	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support Yes	Opera Android ?	Safari iOS ?	Samsung Internet Android Full support Yes

Legend

Full support: Full support
Compatibility unknown: Compatibility unknown