--- title: MediaQueryList slug: Web/API/MediaQueryList tags: - API - CSSOM View - Interface - MediaQueryList - NeedsTranslation - Reference - TopicStub translation_of: Web/API/MediaQueryList ---
A MediaQueryList
object stores information on a media query applied to a document, and handles sending notifications to listeners when the media query state change (i.e. when the media query test starts or stops evaluating to true
).
This makes it possible to observe a document to detect when its media queries change, instead of polling the values periodically, and allows you to programmatically make changes to a document based on media query status.
The new version of the MediaQueryList
interface inherits properties from its parent interface, {{domxref("EventTarget")}}.
true
if the {{domxref("document")}} currently matches the media query list, or false
if not.MediaListQuery
instance in older browsers, for backwards compatibility purposes.The new version of the MediaQueryList
interface inherits methods from its parent interface, {{domxref("EventTarget")}}.
MediaQueryListener
that will run a custom callback function in response to the media query status changing. This is basically an alias for {{domxref("EventTarget.addEventListener()")}}, for backwards compatibility purposes.MediaQueryListener
. This is basically an alias for {{domxref("EventTarget.removeEventListener()")}}, for backwards compatibility purposes.This simple example creates a MediaQueryList
and then sets up a listener to detect when the media query status changes, running a custom function when it does to change the appearence of the page.
var para = document.querySelector('p'); var mql = window.matchMedia('(max-width: 600px)'); function screenTest(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'; } } mql.addListener(screenTest);
Note: You can find this example on GitHub (see the source code, and also see it running live).
Specification | Status | Comment |
---|---|---|
{{SpecName("CSSOM View", "#the-mediaquerylist-interface", "MediaQueryList")}} | {{Spec2("CSSOM View")}} | Initial definition |
{{Compat("api.MediaQueryList")}}