Non-standard: This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

The :-moz-window-inactive CSS pseudo-class is a Mozilla extension that matches any element while it's in an inactive window.

:-moz-window-inactive works in content HTML documents, too.

Note: Prior to the addition of this pseudo-class, giving different styles to background windows was achieved by setting an attribute (active="true") on the top-level XUL chrome window. This attribute is no longer used.


:-moz-window-inactive {
  /* ... */


This example alters the appearance of a box's background depending on whether its window is active or not.


<div id="mybox">
  <p>This is a box!</p>


#mybox {
  background: linear-gradient(to bottom, yellow, cyan);
  width: 200px;
  height: 200px;

#mybox:-moz-window-inactive {
  background: cyan;


The result of this code is shown below. You can view this as a separate page as well.


Not part of any standard.

Browser compatibility

BCD tables only load in the browser

See also