MediaQueryList.onchange

The onchange property of the MediaQueryList interface is an event handler property representing a function that is invoked when the change event fires, i.e when the status of media query support changes. The event object is a MediaQueryListEvent instance, which is recognised as a MediaListQuery instance in older browsers, for backwards compatibility purposes.

Syntax

MediaQueryList.onchange = function() { ... };

Example

var para = document.querySelector('p');
var mql = window.matchMedia('(max-width: 600px)');
mql.onchange = function(e) {
  if (e.matches) {
    /* the viewport is 600 pixels wide or less */
    para.textContent = 'This is a narrow screen — less than 600px wide.';
    document.body.style.backgroundColor = 'red';
  } else {
    /* the viewport is more than than 600 pixels wide */
    para.textContent = 'This is a wide screen — more than 600px wide.';
    document.body.style.backgroundColor = 'blue';
  }
}

Specifications

Browser compatibility

See also

• Media queries
• Using media queries from code
• window.matchMedia()
• MediaQueryList
• MediaQueryListEvent