CSS `z-index` Property

Example

Set the z-index of an image:

img {
    position: absolute;
    left: 0px;
    top: 0px;
    z-index: -1;
}

The z-index property specifies the stacking order of an element.

An element with greater stacking order is always in front of an element with a lower stacking order.

Note: z-index only works on positioned elements (position: absolute, position: relative, or position: fixed).

The numbers in the table specify the first browser version that fully supports the property.

Property
z-index	1.0	4.0	3.0	1.0	4.0

Value	Description
auto	Default. The stacking order is the same as the parent.
number	Sets the stacking order of the element.
inherit	Specifies that the z-index should be inherited from the parent element.