z-index

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The z-index CSS property sets the z-order of a positioned element and its descendants or flex and grid items. Overlapping elements with a larger z-index cover those with a smaller one.

Try it

z-index: auto;

z-index: 1;

z-index: 3;

z-index: 5;

z-index: 7;

<section class="default-example container" id="default-example"> <div id="example-element">Change my z-index</div> <div class="block blue position1">z-index: 6</div> <div class="block blue position2">z-index: 4</div> <div class="block blue position3">z-index: 2</div> <div class="block red position4">z-index: auto</div> <div class="block red position5">z-index: auto</div> <div class="block red position6">z-index: auto</div> </section>

#example-element { top: 15px; left: 15px; width: 180px; height: 230px; position: absolute; /* center the text so it is visible even when z-index is set to auto */ line-height: 215px; font-family: monospace; background-color: #fcfbe5; border: solid 5px #e3e0a1; z-index: auto; color: black; } .container { display: inline-block; width: 250px; position: relative; } .block { width: 150px; height: 50px; position: absolute; font-family: monospace; color: black; } .blue { background-color: #e5e8fc; border: solid 5px #112382; /* move text to the bottom of the box */ line-height: 55px; } .red { background-color: #fce5e7; border: solid 5px #e3a1a7; } .position1 { top: 0; left: 0; z-index: 6; } .position2 { top: 30px; left: 30px; z-index: 4; } .position3 { top: 60px; left: 60px; z-index: 2; } .position4 { top: 150px; left: 0; z-index: auto; } .position5 { top: 180px; left: 30px; z-index: auto; } .position6 { top: 210px; left: 60px; z-index: auto; }

For a positioned box (that is, one with any position other than static), the z-index property specifies:

The stack level of the box in the current stacking context.
Whether the box establishes a local stacking context.

Syntax

css

/* Keyword value */ z-index: auto; /* <integer> values */ z-index: 0; z-index: 3; z-index: 289; z-index: -1; /* Negative values to lower the priority */ /* Global values */ z-index: inherit; z-index: initial; z-index: revert; z-index: revert-layer; z-index: unset;

The z-index property is specified as either the keyword auto or an <integer>.

Values

auto: The box does not establish a new local stacking context. The stack level of the generated box in the current stacking context is 0.
<integer>: This <integer> is the stack level of the generated box in the current stacking context. The box also establishes a local stacking context. This means that the z-indexes of descendants are not compared to the z-indexes of elements outside this element.

Formal definition

Initial value	`auto`
Applies to	positioned elements
Inherited	no
Computed value	as specified
Animation type	an integer
Creates stacking context	yes

Formal syntax

z-index = 
 auto |
 <integer> |
 inherit

Examples

Visually layering elements

HTML

html

<div class="wrapper"> <div class="dashed-box">Dashed box</div> <div class="gold-box">Gold box</div> <div class="green-box">Green box</div> </div>

CSS

css

.wrapper { position: relative; } .dashed-box { position: relative; z-index: 1; border: dashed; height: 8em; margin-bottom: 1em; margin-top: 2em; } .gold-box { position: absolute; z-index: 3; /* put .gold-box above .green-box and .dashed-box */ background: gold; width: 80%; left: 60px; top: 3em; } .green-box { position: absolute; z-index: 2; /* put .green-box above .dashed-box */ background: lightgreen; width: 20%; left: 65%; top: -25px; height: 7em; opacity: 0.9; }

Result

Specifications

Specification
Cascading Style Sheets Level 2 # z-index