---
title: Z-index
description: Use our low-level `z-index` utilities to quickly change the stack level of an element or component.
toc: true
added:
  version: "5.3"
---

## 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]([[docsref:/utilities/position/]]).

<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={`
z-3

z-2

z-1

z-0

z-n1
`} />

## 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]([[docsref:/layout/z-index]]).

## 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]([[docsref:/extend/approach#z-index-scales]]).

## 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.]([[docsref:/utilities/api#using-the-api]])

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