z-index property CSS Reference

---

Definition and Usage

The z-index CSS property specifies the z-order of an element and its descendants. When elements overlap, z-order determines which one covers the other. An element with a larger z-index generally covers an element with a lower one.

For a positioned box, the z-index property specifies:

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

• Initial auto
• Applies to positioned elements
• Inherited no
• Media visual
• Computed Value as specified
• Animatable yes, as an integer
• Canonical order the unique non-ambiguous order defined by the formal grammar

---

Syntax

Formal syntax: auto | <integer>

z-index: auto     /* Keyword value */
z-index: 0        /* <integer> value */
z-index: 3
z-index: 289
z-index: inherit

---

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 the same as its parent's box.

<integer>

This integer is the stack level of the generated box in the current stacking context. The box also establishes a local stacking context in which its stack level is 0. This means that the z-indexes of descendants are not compared to the z-indexes of elements outside this element.

---

Examples

---

Compatibility

Desktop browsers

Mobile browsers