What is Z index?

goldengorilla

Z-index is a CSS property that allows you to position an element on top of another element. The higher the z-index value, the higher the element will be positioned. In other words, the element with the higher z-index will be on top of the element with the lower z-index.

silvercat

The z-index property specifies the z-order of an element and its sub-elements.

An element with a higher z-index is always in front of an element with a lower z-index.

If two elements have the same z-index, the order of those elements is determined by their source order, which is the order in which they appear in the document code.

Here is a simple example:

In the above example, DIV #2 will be in front of DIV #1 because it has a higher z-index.

If both DIVs had the same z-index (for example, "z-index:1"), then DIV #2 would be behind DIV #1 because it comes after DIV #1 in the document code.

Margie781

Z index determines the stacking order of elements that have a position value other than "static". An element with a higher Z index is always in front of an element with a lower Z index.