Utility API
Utilities are single-purpose classes that you combine directly in markup. Stack several on one element, add a breakpoint infix such as d-md-flex to change behaviour from a screen size up, and tune colour states through CSS variables like --ui-bg-opacity, --ui-border-opacity and --ui-link-opacity. The recipes below build complete interface pieces without writing any custom CSS.
1A card made only of utilities
Background, border, radius, padding and shadow utilities stacked on a plain div give you a card without the card component.
Mountain
The world is waiting for you
The new free cancellation lets complex tasks into simple steps in just a few clicks.
<div class="bg-body border rounded-3 p-3 shadow-sm" style="max-width:22rem">
<p class="small text-body-secondary text-uppercase fw-semibold mb-1">Mountain</p>
<h3 class="h5 mb-2">The world is waiting for you</h3>
<p class="mb-0 text-body-secondary">The new free cancellation lets complex tasks into simple steps in just a few clicks.</p>
</div>2Responsive display: d-none d-md-flex
Breakpoint infixes switch a utility on from a screen size up. Resize the window: the toolbar row appears from md, the compact button below it.
d-none d-md-flex and d-flex d-md-none
<div class="border rounded-3 p-3 bg-body-tertiary">
<div class="d-none d-md-flex gap-2">
<button type="button" class="btn btn-sm btn-primary"><i class="bi bi-pencil-square" aria-hidden="true"></i> Edit</button>
<button type="button" class="btn btn-sm btn-outline-secondary"><i class="bi bi-share-fill" aria-hidden="true"></i> Share</button>
<button type="button" class="btn btn-sm btn-outline-danger"><i class="bi bi-trash3-fill" aria-hidden="true"></i> Delete</button>
</div>
<div class="d-flex d-md-none">
<button type="button" class="btn btn-sm btn-primary w-100"><i class="bi bi-three-dots" aria-hidden="true"></i> Actions</button>
</div>
<p class="small text-body-secondary mt-2 mb-0"><code>d-none d-md-flex</code> and <code>d-flex d-md-none</code></p>
</div>3State via --ui-bg-opacity
Every bg-{colour} reads the --ui-bg-opacity variable, so one inline variable fades the fill while the text stays fully opaque.
<div class="d-flex flex-wrap gap-2">
<div class="bg-primary text-white rounded-2 px-3 py-2" style="--ui-bg-opacity:1">
1
</div>
<div class="bg-primary rounded-2 px-3 py-2" style="--ui-bg-opacity:.6">
.6
</div>
<div class="bg-primary rounded-2 px-3 py-2" style="--ui-bg-opacity:.35">
.35
</div>
<div class="bg-primary rounded-2 px-3 py-2" style="--ui-bg-opacity:.15">
.15
</div>
<div class="bg-primary rounded-2 px-3 py-2" style="--ui-bg-opacity:.05">
.05
</div>
</div>4State via --ui-border-opacity
Border colour utilities read --ui-border-opacity; set it inline for values between the border-opacity-* steps.
<div class="row g-2">
<div class="col-6 col-md-3">
<div class="border border-2 border-success rounded-3 p-3 text-center small" style="--ui-border-opacity:1">
1
</div>
</div>
<div class="col-6 col-md-3">
<div class="border border-2 border-success rounded-3 p-3 text-center small" style="--ui-border-opacity:.6">
.6
</div>
</div>
<div class="col-6 col-md-3">
<div class="border border-2 border-success rounded-3 p-3 text-center small" style="--ui-border-opacity:.3">
.3
</div>
</div>
<div class="col-6 col-md-3">
<div class="border border-2 border-success rounded-3 p-3 text-center small" style="--ui-border-opacity:.1">
.1
</div>
</div>
</div>5State via --ui-link-opacity
Coloured links read --ui-link-opacity. Combine it with the -hover utilities for a link that brightens on hover.
- Travel insurance --ui-link-opacity:.5
- Best price guarantee 50, 100 on hover
- The world is waiting for you link-opacity-75
<ul class="list-unstyled mb-0 d-grid gap-2">
<li><a href="#" class="link-primary" style="--ui-link-opacity:.5">Travel insurance</a> <span class="small text-body-secondary">--ui-link-opacity:.5</span></li>
<li><a href="#" class="link-primary link-opacity-50 link-opacity-100-hover">Best price guarantee</a> <span class="small text-body-secondary">50, 100 on hover</span></li>
<li><a href="#" class="link-danger link-opacity-75">The world is waiting for you</a> <span class="small text-body-secondary">link-opacity-75</span></li>
</ul>6Media object
d-flex with gap, flex-shrink-0 on the image and flex-grow-1 on the text is the classic comment or list row.
A friendly journey helps results you can measure from the very first day.
<div class="d-flex gap-3 align-items-start border rounded-3 p-3">
<img src="../assets/img/avatar-12.svg" alt="Ava Brennan" width="48" height="48" class="rounded-circle flex-shrink-0">
<div class="flex-grow-1">
<div class="d-flex justify-content-between">
<strong>Ava Brennan</strong><small class="text-body-secondary">2 days ago</small>
</div>
<p class="mb-0 small">A friendly journey helps results you can measure from the very first day.</p>
</div>
</div>7Status badges without the badge component
Subtle backgrounds, emphasis text, small padding and rounded-pill compose a soft status label.
<div class="d-flex flex-wrap gap-2">
<span class="d-inline-flex align-items-center gap-1 px-2 py-1 rounded-pill small fw-medium bg-success-subtle text-success-emphasis border border-success-subtle"><i class="bi bi-check-circle-fill" aria-hidden="true"></i> Active</span> <span class="d-inline-flex align-items-center gap-1 px-2 py-1 rounded-pill small fw-medium bg-warning-subtle text-warning-emphasis border border-warning-subtle"><i class="bi bi-clock-fill" aria-hidden="true"></i> Pending</span> <span class="d-inline-flex align-items-center gap-1 px-2 py-1 rounded-pill small fw-medium bg-danger-subtle text-danger-emphasis border border-danger-subtle"><i class="bi bi-x-circle-fill" aria-hidden="true"></i> Blocked</span>
</div>8Stat tile
Font size, weight, line height and colour utilities turn three lines of text into a dashboard metric.
<div class="row g-3">
<div class="col-sm-6 col-lg-4">
<div class="p-3 rounded-4 bg-body-tertiary border">
<div class="d-flex justify-content-between align-items-center mb-2">
<span class="small text-body-secondary fw-medium">Revenue</span><span class="text-primary fs-5"><i class="bi bi-graph-up-arrow" aria-hidden="true"></i></span>
</div>
<div class="fs-3 fw-bold lh-1">
$25,201.58
</div>
<div class="small text-success mt-1">
<i class="bi bi-arrow-up" aria-hidden="true"></i> +83% this month
</div>
</div>
</div>
<div class="col-sm-6 col-lg-4">
<div class="p-3 rounded-4 bg-body-tertiary border">
<div class="d-flex justify-content-between align-items-center mb-2">
<span class="small text-body-secondary fw-medium">Customers</span><span class="text-info fs-5"><i class="bi bi-people-fill" aria-hidden="true"></i></span>
</div>
<div class="fs-3 fw-bold lh-1">
7.8k
</div>
<div class="small text-danger mt-1">
<i class="bi bi-arrow-down" aria-hidden="true"></i> -6% this month
</div>
</div>
</div>
</div>9Avatar with a status dot
position-relative on the wrapper, then position-absolute, bottom-0 / end-0 and a white border for the online dot.
Online
Away
<div class="d-flex gap-4 align-items-center">
<div class="position-relative d-inline-block">
<img src="../assets/img/avatar-9.svg" alt="Lucas Ibrahim" width="56" height="56" class="rounded-circle"> <span class="position-absolute bottom-0 end-0 p-2 bg-success border border-2 border-white rounded-circle"><span class="visually-hidden">Online</span></span>
</div>
<div class="position-relative d-inline-block">
<img src="../assets/img/avatar-3.svg" alt="Owen Quinn" width="56" height="56" class="rounded-circle"> <span class="position-absolute bottom-0 end-0 p-2 bg-secondary border border-2 border-white rounded-circle"><span class="visually-hidden">Away</span></span>
</div>
</div>10Responsive alignment
text-center on phones and text-md-start from md: a hero block that centres only where it should.
Find your next escape
A calm experience turns decisions quicker and clearer without the usual hassle.
Get started<div class="p-4 rounded-4 bg-primary-subtle text-center text-md-start">
<h3 class="h4 fw-bold text-primary-emphasis">Find your next escape</h3>
<p class="mb-3 text-primary-emphasis">A calm experience turns decisions quicker and clearer without the usual hassle.</p>
<a href="#" class="btn btn-primary">Get started</a>
</div>11Stack on phones, row on tablets
flex-column flex-md-row with gap-3: three blocks stack on small screens and line up from md.
<div class="d-flex flex-column flex-md-row gap-3">
<div class="flex-fill p-3 rounded-3 border bg-body-tertiary">
<i class="bi bi-lightning-charge-fill" aria-hidden="true"></i> <strong>Curated stays</strong>
</div>
<div class="flex-fill p-3 rounded-3 border bg-body-tertiary">
<i class="bi bi-shield-check" aria-hidden="true"></i> <strong>Best price guarantee</strong>
</div>
<div class="flex-fill p-3 rounded-3 border bg-body-tertiary">
<i class="bi bi-cloud-arrow-up-fill" aria-hidden="true"></i> <strong>Best price guarantee</strong>
</div>
</div>12Callout from border-start
A single side border with a thick width and a theme colour makes a note or warning callout.
Our guided tours shows complex tasks into simple steps for teams of every size.
<div class="border-start border-4 border-warning bg-warning-subtle rounded-end-3 p-3">
<div class="fw-semibold text-warning-emphasis mb-1">
<i class="bi bi-exclamation-triangle-fill" aria-hidden="true"></i> Heads up
</div>
<p class="mb-0 small text-warning-emphasis">Our guided tours shows complex tasks into simple steps for teams of every size.</p>
</div>13Settings row
justify-content-between and align-items-center place a label on the left and a control on the right.
<div class="border rounded-3">
<div class="d-flex justify-content-between align-items-center p-3 border-bottom">
<div>
<div class="fw-medium">
Email alerts
</div>
<div class="small text-body-secondary">
Daily summary at 12:45
</div>
</div>
<span class="px-2 py-1 rounded-pill small bg-success text-white">On</span>
</div>
<div class="d-flex justify-content-between align-items-center p-3">
<div>
<div class="fw-medium">
Push notifications
</div>
<div class="small text-body-secondary">
Only mentions
</div>
</div>
<span class="px-2 py-1 rounded-pill small bg-body-secondary text-body-secondary">Off</span>
</div>
</div>14Announcement bar
text-bg-dark sets a contrasting text colour with the background; small and gap utilities do the rest.
<div class="text-bg-dark rounded-3 px-3 py-2 d-flex flex-wrap align-items-center justify-content-center gap-2 small">
<span class="badge text-bg-warning">New</span> <span>Find your next escape</span> <a href="#" class="link-light link-offset-2 fw-semibold">Read more</a>
</div>15Filter chips that wrap
flex-wrap with gap-2 lets a row of chips flow onto new lines without margin hacks.
<div class="d-flex flex-wrap gap-2">
<span class="px-3 py-1 rounded-pill bg-primary text-white small">All</span> <span class="px-3 py-1 rounded-pill border small">insights</span> <span class="px-3 py-1 rounded-pill border small">Mountain</span> <span class="px-3 py-1 rounded-pill border small">powerful</span> <span class="px-3 py-1 rounded-pill border small">routine</span>
</div>16Product line item
A thumbnail, a truncated title and a right-aligned price: overflow-hidden on the middle column lets text-truncate work in flex.
<div class="d-flex align-items-center gap-3 border rounded-3 p-2" style="max-width:28rem">
<img src="../assets/img/product-5.svg" alt="Mountain lodge" width="56" height="56" class="rounded-2 object-fit-cover flex-shrink-0">
<div class="flex-grow-1 overflow-hidden">
<div class="fw-medium text-truncate">
Mountain lodge - elegant edition
</div>
<div class="small text-body-secondary">
City
</div>
</div>
<div class="fw-bold text-nowrap">
$409.00
</div>
</div>17Responsive spacing
p-2 p-md-4 and mb-2 mb-md-3: tighter padding on phones, roomier from md, no media query needed.
How we rebuilt our launch
Our guided tours gives every detail in view wherever you are. This friendly launch keeps your work organised wherever you are.
<div class="border rounded-4 p-2 p-md-4 bg-body-tertiary">
<h3 class="h6 mb-2 mb-md-3">How we rebuilt our launch</h3>
<p class="mb-0 small">Our guided tours gives every detail in view wherever you are. This friendly launch keeps your work organised wherever you are.</p>
</div>18Underline that appears on hover
link-underline-opacity-0 hides the underline, the -hover variants bring it back with a little offset.
<nav class="d-flex flex-wrap gap-3" aria-label="Footer">
<a href="#" class="link-body-emphasis link-offset-2 link-underline-opacity-0 link-underline-opacity-100-hover">About</a> <a href="#" class="link-body-emphasis link-offset-2 link-underline-opacity-0 link-underline-opacity-100-hover">Pricing</a> <a href="#" class="link-body-emphasis link-offset-2 link-underline-opacity-0 link-underline-opacity-100-hover">Support</a> <a href="#" class="link-body-emphasis link-offset-2 link-underline-opacity-0 link-underline-opacity-100-hover">Careers</a>
</nav>19Image with a text overlay
position-relative wrapper, an absolutely placed caption at bottom-0 and bg-dark with --ui-bg-opacity for the scrim.
<div class="position-relative rounded-4 overflow-hidden" style="max-width:26rem">
<img src="../assets/img/photo-6.svg" alt="Explore more, worry less" class="w-100 d-block">
<div class="position-absolute bottom-0 start-0 end-0 bg-dark text-white p-3" style="--ui-bg-opacity:.6">
<div class="small text-white-50">
Seoul
</div>
<div class="fw-semibold">
Stay somewhere unforgettable
</div>
</div>
</div>20Empty state panel
A centred flex column with a large icon, muted text and one action, built from spacing and text utilities.
No files yet
The new best price guarantee turns your work organised without the usual hassle.
<div class="d-flex flex-column align-items-center text-center py-5 px-3 border rounded-4 bg-body-tertiary">
<div class="fs-1 text-body-tertiary mb-2">
<i class="bi bi-folder2-open" aria-hidden="true"></i>
</div>
<h3 class="h6 fw-semibold mb-1">No files yet</h3>
<p class="small text-body-secondary mb-3">The new best price guarantee turns your work organised without the usual hassle.</p>
<button type="button" class="btn btn-sm btn-primary"><i class="bi bi-cloud-arrow-up-fill" aria-hidden="true"></i> Upload</button>
</div>