What is Z-Index?

Z-index is a CSS property used to control the stacking order of elements on a webpage. It determines which elements will appear on top of others when they overlap. The higher the z-index value, the closer the element is to the front of the stacking order. Elements with a lower z-index value will appear behind those with a higher value.

Z-index only works on elements that have a positioning property set, such as relative, absolute, or fixed. It is commonly used in web design to manage layers, such as creating dropdown menus, modals, or tooltips, ensuring they appear above other content on the page.