Z-index

Z-index utilities change the stacking order of positioned elements: z-n1 sends an element behind its context, z-0 creates a base layer and z-1, z-2 and z-3 bring elements forward. They only apply to elements with a position, so pair them with position-relative or position-absolute.

1Z-index scale

z-n1, z-0, z-1, z-2 and z-3 stack positioned elements from back to front.

z-3

z-2

z-1

z-0

z-n1

<div class="position-relative" style="height:170px">
  <div class="position-absolute rounded-3 p-2 small fw-semibold border bg-body-secondary z-3" style="top:0;left:0;width:150px;height:90px">
    z-3
  </div>
  <div class="position-absolute rounded-3 p-2 small fw-semibold border bg-primary-subtle z-2" style="top:20px;left:40px;width:150px;height:90px">
    z-2
  </div>
  <div class="position-absolute rounded-3 p-2 small fw-semibold border bg-success-subtle z-1" style="top:40px;left:80px;width:150px;height:90px">
    z-1
  </div>
  <div class="position-absolute rounded-3 p-2 small fw-semibold border bg-warning-subtle z-0" style="top:60px;left:120px;width:150px;height:90px">
    z-0
  </div>
  <div class="position-absolute rounded-3 p-2 small fw-semibold border bg-danger-subtle z-n1" style="top:80px;left:160px;width:150px;height:90px">
    z-n1
  </div>
</div>

2Order without z-index

Without z-index, later elements paint on top of earlier ones.

first

second (on top)

<div class="position-relative" style="height:130px">
  <div class="position-absolute rounded-3 p-2 small fw-semibold border bg-primary-subtle" style="top:0;left:0;width:160px;height:90px">
    first
  </div>
  <div class="position-absolute rounded-3 p-2 small fw-semibold border bg-info-subtle" style="top:30px;left:60px;width:160px;height:90px">
    second (on top)
  </div>
</div>

3Bring the first one forward

z-1 on the first element puts it above its later sibling.

first, z-1

second

<div class="position-relative" style="height:130px">
  <div class="position-absolute rounded-3 p-2 small fw-semibold border bg-primary-subtle z-1" style="top:0;left:0;width:160px;height:90px">
    first, z-1
  </div>
  <div class="position-absolute rounded-3 p-2 small fw-semibold border bg-info-subtle" style="top:30px;left:60px;width:160px;height:90px">
    second
  </div>
</div>

4Background shape behind content

z-n1 places a decorative shape behind the text of its positioned parent, which uses z-0 to form a stacking context.

See every transaction in real time

Payroll runs on time, with tax and pension payments handled for you.

<div class="position-relative z-0 p-4">
  <div class="position-absolute top-0 start-0 bg-primary-subtle rounded-circle z-n1" style="width:120px;height:120px">
  </div>
  <h3 class="h5 fw-semibold">See every transaction in real time</h3>
  <p class="small mb-0">Payroll runs on time, with tax and pension payments handled for you.</p>
</div>

5Overlapping avatars

Decreasing z-index keeps the first avatar on top of the stack.

<div class="d-flex">
  <img src="../assets/img/avatar-6.svg" alt="Freya Nguyen" width="44" height="44" class="rounded-circle border border-2 border-white position-relative z-3"> <img src="../assets/img/avatar-7.svg" alt="Nora Morgan" width="44" height="44" class="rounded-circle border border-2 border-white position-relative z-2" style="margin-left:-14px"> <img src="../assets/img/avatar-8.svg" alt="Arjun Ashford" width="44" height="44" class="rounded-circle border border-2 border-white position-relative z-1" style="margin-left:-14px"> <img src="../assets/img/avatar-9.svg" alt="Ethan Okafor" width="44" height="44" class="rounded-circle border border-2 border-white position-relative z-0" style="margin-left:-14px"> 
</div>

6Active button above its neighbours

In joined button rows the active one gets z-1 so its border is not hidden.

<div class="d-flex">
  <button type="button" class="btn btn-outline-secondary rounded-0 rounded-start position-relative">Day</button>
  <button type="button" class="btn btn-outline-primary rounded-0 position-relative z-1 active" style="margin-left:-1px" aria-pressed="true">Week</button>
  <button type="button" class="btn btn-outline-secondary rounded-0 rounded-end position-relative" style="margin-left:-1px">Month</button>
</div>

7Badge over a card image

The badge uses z-2 so it stays above an overlay with z-1.

The small habits that make a big difference

tips

<div class="position-relative rounded-4 overflow-hidden" style="max-width:20rem">
  <img src="https://images.unsplash.com/photo-1758518730083-4c12527b6742?auto=format&fit=crop&w=1200&h=800&q=70" alt="The small habits that make a big difference" class="w-100 d-block"> 
  <div class="position-absolute top-0 start-0 w-100 h-100 bg-dark bg-opacity-25 z-1">
  </div>
  <span class="position-absolute top-0 start-0 m-2 badge text-bg-warning z-2">tips</span> 
</div>

8Floating label above a chart

A z-3 label stays above grid lines and bars.

Peak 547

<div class="position-relative border rounded-3 p-3" style="height:150px">
  <div class="position-absolute start-0 end-0 border-top z-0" style="top:50px">
  </div>
  <div class="position-absolute start-0 end-0 border-top z-0" style="top:100px">
  </div>
  <div class="d-flex align-items-end gap-2 h-100 position-relative z-1">
    <div class="bg-primary-subtle flex-fill h-50 rounded-top">
    </div>
    <div class="bg-primary flex-fill h-75 rounded-top">
    </div>
    <div class="bg-primary-subtle flex-fill h-25 rounded-top">
    </div>
  </div>
  <span class="position-absolute top-0 start-50 translate-middle-x mt-2 badge text-bg-dark z-3">Peak 547</span> 
</div>

9Sticky header layer

A sticky header with z-2 stays above rows that have their own positioned badges.

Team

Elena Patel new

Lea Fischer

Kai Duarte

Diego Alvarez

Noah Morgan

<div class="border rounded-3 overflow-auto" style="height:160px">
  <div class="sticky-top z-2 bg-body-secondary px-3 py-2 small fw-semibold">
    Team
  </div>
  <div class="px-3 py-2 border-bottom position-relative">
    Elena Patel <span class="badge text-bg-success position-relative z-1">new</span>
  </div>
  <div class="px-3 py-2 border-bottom">
    Lea Fischer
  </div>
  <div class="px-3 py-2 border-bottom">
    Kai Duarte
  </div>
  <div class="px-3 py-2 border-bottom">
    Diego Alvarez
  </div>
  <div class="px-3 py-2">
    Noah Morgan
  </div>
</div>

10Cards in a fan

Rotated cards stacked with z-1 to z-3.

z-1

z-2

z-3

<div class="position-relative mx-auto" style="height:170px;max-width:18rem">
  <div class="position-absolute top-50 start-50 bg-body border rounded-3 shadow-sm p-3 z-1" style="width:140px;transform:translate(-80%,-50%) rotate(-10deg)">
    <div class="small">
      <code class="small">z-1</code>
    </div>
  </div>
  <div class="position-absolute top-50 start-50 bg-body border rounded-3 shadow-sm p-3 z-2" style="width:140px;transform:translate(-50%,-50%)">
    <div class="small">
      <code class="small">z-2</code>
    </div>
  </div>
  <div class="position-absolute top-50 start-50 bg-body border rounded-3 shadow-sm p-3 z-3" style="width:140px;transform:translate(-20%,-50%) rotate(10deg)">
    <div class="small fw-bold">
      <code class="small">z-3</code>
    </div>
  </div>
</div>

11Image behind a heading

The hero image sits on z-n1 inside a z-0 context, the text sits on top.

Business banking without the paperwork

Open a business account online in about ten minutes, with no branch visit.

<div class="position-relative z-0 rounded-4 overflow-hidden p-4 text-white bg-dark" style="min-height:180px">
  <img src="https://images.unsplash.com/photo-1758518730083-4c12527b6742?auto=format&fit=crop&w=1600&h=700&q=70" alt="" class="position-absolute top-0 start-0 w-100 h-100 object-fit-cover z-n1"> 
  <div class="position-absolute top-0 start-0 w-100 h-100 bg-dark bg-opacity-50 z-n1">
  </div>
  <h3 class="h4 fw-bold">Business banking without the paperwork</h3>
  <p class="mb-0 small">Open a business account online in about ten minutes, with no branch visit.</p>
</div>

12Focus ring over siblings

List group items lift their active item with z-1 so its border shows on both edges.

Cards
Payments
Payments

<ul class="list-unstyled mb-0" style="max-width:18rem">
  <li class="border px-3 py-2 rounded-top position-relative">Cards</li>
  <li class="border border-primary bg-primary-subtle px-3 py-2 position-relative z-1" style="margin-top:-1px">Payments</li>
  <li class="border px-3 py-2 rounded-bottom position-relative" style="margin-top:-1px">Payments</li>
</ul>

13Notification over a header

A count badge on z-3 overlaps the next header item.

<div class="d-flex gap-3 border rounded-3 p-3 align-items-center">
  <span class="position-relative fs-4"><i class="bi bi-bell" aria-hidden="true"></i><span class="position-absolute top-0 start-100 translate-middle badge rounded-pill text-bg-danger z-3 fs-6">41</span></span> <span class="position-relative fs-4 bg-body rounded-2 px-2"><i class="bi bi-chat-dots" aria-hidden="true"></i></span> 
</div>

14Stacked paper effect

Two layers on z-n1 behind a card look like a pile of pages.

Invoices

27 documents

<div class="position-relative z-0 mx-auto" style="max-width:20rem">
  <div class="position-absolute top-0 start-0 w-100 h-100 bg-body-secondary border rounded-3 z-n1" style="transform:translate(8px,8px)">
  </div>
  <div class="position-absolute top-0 start-0 w-100 h-100 bg-body-tertiary border rounded-3 z-n1" style="transform:translate(4px,4px)">
  </div>
  <div class="bg-body border rounded-3 p-3">
    <div class="fw-semibold">
      Invoices
    </div>
    <div class="small text-body-secondary">
      27 documents
    </div>
  </div>
</div>

15Overlapping sections

A card with z-1 overlaps the coloured band above it via a negative top offset.

Smarter payments for growing companies

Accounting sync keeps your books up to date without manual exports.

<div>
  <div class="text-bg-primary rounded-top-4 p-4 pb-5">
    <h3 class="h5 mb-0">Smarter payments for growing companies</h3>
  </div>
  <div class="position-relative z-1 bg-body border rounded-4 shadow-sm p-3 mx-3" style="margin-top:-2rem">
    Accounting sync keeps your books up to date without manual exports.
  </div>
</div>

16Corner ribbon above a border

A z-2 ribbon overlaps the card border.

Active

Business accounts

Cash flow forecasts show where you will be next month, not just today.

<div class="position-relative border border-2 rounded-4 p-4" style="max-width:18rem">
  <span class="position-absolute top-0 end-0 translate-middle-y me-3 badge text-bg-success z-2">Active</span> 
  <div class="fw-semibold">
    Business accounts
  </div>
  <div class="small text-body-secondary">
    Cash flow forecasts show where you will be next month, not just today.
  </div>
</div>

17Hover card layer (static preview)

A preview popover on z-3 overlapping a list.

Liam Ashford
Chloe Delgado
Finn Carter

We keep things simple, so you can focus on what matters to you.

<div class="position-relative" style="height:150px">
  <ul class="list-unstyled border rounded-3 mb-0">
    <li class="px-3 py-2 border-bottom">Liam Ashford</li>
    <li class="px-3 py-2 border-bottom">Chloe Delgado</li>
    <li class="px-3 py-2">Finn Carter</li>
  </ul>
  <div class="position-absolute bg-body border rounded-3 shadow p-3 z-3 small" style="top:20px;left:40%;width:13rem">
    We keep things simple, so you can focus on what matters to you.
  </div>
</div>

18Z-index needs a position

z-* only works on positioned elements: the left box has no position, the right one has position-relative.

z-3, static (ignored)

z-3, position-relative

<div class="row g-2">
  <div class="col-6">
    <div class="bg-info-subtle border rounded-3 p-3 z-3 small">
      z-3, static (ignored)
    </div>
  </div>
  <div class="col-6">
    <div class="bg-info-subtle border rounded-3 p-3 z-3 position-relative small">
      z-3, position-relative
    </div>
  </div>
</div>

19Price tag over a product

A z-1 price tag over the product image and a z-2 heart button above it.

$97.55

<div class="position-relative rounded-4 overflow-hidden border" style="max-width:16rem">
  <img src="../assets/img/product-11.svg" alt="Tax reserve" class="w-100 d-block"> <span class="position-absolute bottom-0 start-0 m-2 badge text-bg-dark z-1">$97.55</span> 
  <button type="button" class="btn btn-light btn-sm rounded-circle position-absolute top-0 end-0 m-2 z-2" aria-label="Save"><i class="bi bi-heart" aria-hidden="true"></i></button>
</div>

20Dropdown above content

An open menu at z-3 overlaps the panel below it.

Newest
Price low to high
Rating

Issue virtual and physical cards to your team with limits you control. We measure success by how many members come back and tell their friends.

<div class="position-relative" style="height:170px">
  <button type="button" class="btn btn-sm btn-outline-secondary"><i class="bi bi-sort-down" aria-hidden="true"></i> Sort</button>
  <ul class="position-absolute list-unstyled bg-body border rounded-3 shadow py-1 mt-1 z-3 small mb-0" style="width:11rem">
    <li class="px-3 py-1">Newest</li>
    <li class="px-3 py-1 bg-primary-subtle">Price low to high</li>
    <li class="px-3 py-1">Rating</li>
  </ul>
  <div class="bg-body-tertiary border rounded-3 p-3 mt-2 small">
    Issue virtual and physical cards to your team with limits you control. We measure success by how many members come back and tell their friends.
  </div>
</div>