auxclick

Example

In this example we define two event handler functions — onclick and onauxclick. The former changes the color of the button background, while the latter changes the button foreground (text) color. You can see the two functions in action by trying the demo out with a multi-button mouse (see it live on GitHub; also see the source code).

var button = document.querySelector('button');
var html = document.querySelector('html');
function random(number) {
  return Math.floor(Math.random() * number);
}
button.onclick = function() {
  var rndCol = 'rgb(' + random(255) + ',' + random(255) + ',' + random(255) + ')';
  button.style.backgroundColor = rndCol;
};
button.onauxclick = function() {
  var rndCol = 'rgb(' + random(255) + ',' + random(255) + ',' + random(255) + ')';
  button.style.color = rndCol;
}

Preventing default actions

For the vast majority of browsers that map middle click to opening a link in a new tab, including Firefox, it is possible to cancel this behaviour by calling preventDefault from within an auxclick event handler.

When listening for auxclick events originating on elements that do not support input or navigation, you will often want to explicitly prevent other default actions mapped to the down action of the middle mouse button. On Windows this is usually autoscroll, and on Mac OS and Linux this is usually clipboard paste. This can be done by preventing the default behaviour of the mousedown or pointerdown event.

Additionally, you may need to avoid opening a system context menu after a right click. Due to timing differences between operating systems, this too is not a preventable default behaviour of auxclick. Instead this can be done by preventing the default behaviour of the contextmenu event.

Inheritance

The auxclick event object implements the MouseEvent interface, which in turn implements the Event interface — it has available the properties and methods defined on both these interfaces.

Specification

Browser Compatibility