Web/API/GlobalEventHandlers/onmousedown

The onmousedown property of the GlobalEventHandlers mixin is an EventHandler that processes mousedown events.

The mousedown event fires when the user depresses the mouse button.

Note: The opposite of onmousedown is onmouseup.

Syntax

target.onmousedown = functionRef;

Value

functionRef is a function name or a function expression. The function receives a MouseEvent object as its sole argument.

Example

This example reveals part of an image when you press and hold a mouse button. It uses the onmousedown, onmouseup, and onmousemove event handlers.

HTML

<div class="container">
  <div class="view" hidden></div>
  <img src="https://interactive-examples.mdn.mozilla.net/media/examples/gecko-320-213.jpg">
</div>

CSS

.container {
  width: 320px;
  height: 213px;
  background: black;
}

.view {
  position: absolute;
  width: 100px;
  height: 100px;
  background: white;
  border-radius: 50%;
}

img {
  mix-blend-mode: darken;
}

JavaScript

function showView(event) {
  view.removeAttribute('hidden');
  view.style.left = event.clientX - 50 + 'px';
  view.style.top = event.clientY - 50 + 'px';
  event.preventDefault();
}

function moveView(event) {
  view.style.left = event.clientX - 50 + 'px';
  view.style.top = event.clientY - 50 + 'px';
}

function hideView(event) {
  view.setAttribute('hidden', '');
}

const container = document.querySelector('.container');
const view = document.querySelector('.view');

container.onmousedown = showView;
container.onmousemove = moveView;
document.onmouseup = hideView;

Result

Specification

Specification	Status	Comment
HTML Living StandardThe definition of 'onmousedown' in that specification.	Living Standard

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
`onmousedown`	Chrome Full support Yes	Edge Full support 12	Firefox Full support Yes	IE Full support Yes	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support Yes	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes

Legend

Full support: Full support