Z-index

Example

Use z-index utilities to stack elements on top of one another. Requires a position value other than static, which can be set with custom styles or using our position utilities.

<Callout> We call these “low-level” `z-index` utilities because of their default values of `-1` through `3`, which we use for the layout of overlapping components. High-level `z-index` values are used for overlay components like modals and tooltips. </Callout>

<Example class="bd-example-zindex-levels position-relative" code={`<div class="z-3 position-absolute p-5 rounded-3"><span>z-3</span></div>

<div class="z-2 position-absolute p-5 rounded-3"><span>z-2</span></div> <div class="z-1 position-absolute p-5 rounded-3"><span>z-1</span></div> <div class="z-0 position-absolute p-5 rounded-3"><span>z-0</span></div> <div class="z-n1 position-absolute p-5 rounded-3"><span>z-n1</span></div>`} />

Overlays

Bootstrap overlay components—dropdown, modal, offcanvas, popover, toast, and tooltip—all have their own z-index values to ensure a usable experience with competing “layers” of an interface.

Read about them in the z-index layout page.

Component approach

On some components, we use our low-level z-index values to manage repeating elements that overlap one another (like buttons in a button group or items in a list group).

Learn about our z-index approach.

CSS

Sass maps

Customize this Sass map to change the available values and generated utilities.

<ScssDocs name="zindex-levels-map" file="scss/_variables.scss" />

Sass utilities API

Position utilities are declared in our utilities API in scss/_utilities.scss. Learn how to use the utilities API.

<ScssDocs name="utils-zindex" file="scss/_utilities.scss" />