Collapse shows and hides content with a short animation. Point a button or link at the target with data-ui-toggle="collapse", keep aria-expanded and aria-controls in sync, and use it for read-more text, filter panels, sub-menus and expandable rows.
1Button toggle
A button with data-ui-toggle="collapse" shows and hides the target.
<button class="btn btn-primary" type="button" data-ui-toggle="collapse" data-ui-target="#collapse-908" aria-expanded="false" aria-controls="collapse-908">Toggle details</button>
<div class="ui-collapse" id="collapse-908">
<div class="card card-body mt-2">
Ninety cents of every dollar goes directly to the projects you support. We measure success by how many donors come back and tell their friends.
</div>
</div>2Link toggle
A link with href="#id" and role="button" works the same way.
Friendly people answer your questions quickly, by phone, chat or email.
<a class="link-primary" data-ui-toggle="collapse" href="#collapse-909" role="button" aria-expanded="false" aria-controls="collapse-909"><i class="bi bi-info-circle" aria-hidden="true"></i> What does this mean?</a>
<div class="ui-collapse" id="collapse-909">
<p class="small text-muted mt-2 mb-0">Friendly people answer your questions quickly, by phone, chat or email.</p>
</div>3Horizontal collapse
collapse-horizontal animates the width; the content needs a fixed width.
<button class="btn btn-outline-primary" type="button" data-ui-toggle="collapse" data-ui-target="#collapse-910" aria-expanded="false" aria-controls="collapse-910">Toggle width</button>
<div style="min-height: 110px;" class="mt-2">
<div class="ui-collapse collapse-horizontal" id="collapse-910">
<div class="card card-body" style="width: 260px;">
We listen first, then build a plan around what you actually need.
</div>
</div>
</div>4Multiple targets
One button can toggle several elements by targeting a shared class.
<div class="flex flex-wrap gap-2 mb-2">
<button class="btn btn-outline-secondary" type="button" data-ui-toggle="collapse" data-ui-target="#multi-911" aria-expanded="false" aria-controls="multi-911">Toggle first</button>
<button class="btn btn-outline-secondary" type="button" data-ui-toggle="collapse" data-ui-target="#multi-912" aria-expanded="false" aria-controls="multi-912">Toggle second</button>
<button class="btn btn-primary" type="button" data-ui-toggle="collapse" data-ui-target=".multi-group-913" aria-expanded="false" aria-controls="multi-911 multi-912">Toggle both</button>
</div>
<div class="row g-2">
<div class="col-sm-6">
<div class="ui-collapse multi-group-913" id="multi-911">
<div class="card card-body">
Monthly gifts let us plan ahead and respond quickly when disaster strikes.
</div>
</div>
</div>
<div class="col-sm-6">
<div class="ui-collapse multi-group-913" id="multi-912">
<div class="card card-body">
Every donation is tax-deductible, and receipts arrive by email instantly.
</div>
</div>
</div>
</div>5Read more
Show the first part of a text and reveal the rest on demand.
Our team has done this many times, so you never have to guess. Leave a gift in your will and help future generations.
We have helped more than two hundred thousand people since we started. We measure success by how many donors come back and tell their friends. You receive photos and updates showing exactly what your donation achieved.
<p class="mb-1">Our team has done this many times, so you never have to guess. Leave a gift in your will and help future generations.</p>
<div class="ui-collapse" id="more-914">
<p class="mb-1">We have helped more than two hundred thousand people since we started. We measure success by how many donors come back and tell their friends. You receive photos and updates showing exactly what your donation achieved.</p>
</div>
<button class="btn btn-link px-0 ca-more" type="button" data-ui-toggle="collapse" data-ui-target="#more-914" aria-expanded="false" aria-controls="more-914"><span class="ca-more-show">Read more</span><span class="ca-more-hide">Show less</span></button>6Filter panel
A filter button above a table reveals extra search fields.
<div class="flex gap-2">
<input type="search" class="form-control" placeholder="Search orders" aria-label="Search orders" style="max-width: 280px;">
<button class="btn btn-outline-secondary" type="button" data-ui-toggle="collapse" data-ui-target="#filters-915" aria-expanded="false" aria-controls="filters-915"><i class="bi bi-sliders" aria-hidden="true"></i> Filters</button>
</div>
<div class="ui-collapse" id="filters-915">
<div class="border rounded-md p-4 mt-2 row g-2">
<div class="col-sm-6">
<label class="form-label small" for="filter-q-916">Customer</label>
<input class="form-control form-control-sm" id="filter-q-916" type="text" placeholder="Ivy Alvarez">
</div>
<div class="col-sm-6">
<label class="form-label small" for="filter-status-917">Status</label>
<select class="form-select form-select-sm" id="filter-status-917">
<option>Any</option>
<option>Paid</option>
<option>Pending</option>
<option>Refunded</option>
</select>
</div>
<div class="col-12 text-end">
<button type="button" class="btn btn-primary btn-sm">Apply</button>
</div>
</div>
</div>7Sidebar sub-menus
Nested navigation where each section expands to show its links.
<nav class="border rounded-md p-2" style="max-width: 260px;" aria-label="Admin menu">
<ul class="nav flex-col">
<li class="nav-item"><a class="nav-link link-body-emphasis" href="#"><i class="bi bi-house" aria-hidden="true"></i> Home</a></li>
<li class="nav-item"><a class="nav-link link-body-emphasis flex justify-between" data-ui-toggle="collapse" href="#menu-918" role="button" aria-expanded="true" aria-controls="menu-918"><span><i class="bi bi-bag" aria-hidden="true"></i> Sales</span><i class="bi bi-chevron-down" aria-hidden="true"></i></a><div class="ui-collapse show" id="menu-918"><ul class="nav flex-col ms-6 small"><li class="nav-item"><a class="nav-link py-1" href="#">Orders</a></li><li class="nav-item"><a class="nav-link py-1" href="#">Invoices</a></li></ul></div></li>
<li class="nav-item"><a class="nav-link link-body-emphasis flex justify-between" data-ui-toggle="collapse" href="#menu-919" role="button" aria-expanded="false" aria-controls="menu-919"><span><i class="bi bi-bar-chart" aria-hidden="true"></i> Reports</span><i class="bi bi-chevron-down" aria-hidden="true"></i></a><div class="ui-collapse" id="menu-919"><ul class="nav flex-col ms-6 small"><li class="nav-item"><a class="nav-link py-1" href="#">Weekly</a></li><li class="nav-item"><a class="nav-link py-1" href="#">Monthly</a></li></ul></div></li>
</ul>
</nav>8Expandable table rows
A detail row under each table row opens with a small toggle.
| Invoice | Amount | Details |
|---|---|---|
| #ORD-4644 | $510.95 | |
Billed to Samir Patel, Prague. Due Feb 8, 2027. | ||
| #INV-8527 | $464.09 | |
Billed to Ava Carter, Auckland. Due Nov 26, 2026. | ||
<div class="table-responsive">
<table class="table align-middle mb-0">
<thead>
<tr>
<th scope="col">Invoice</th>
<th scope="col">Amount</th>
<th scope="col"><span class="sr-only">Details</span></th>
</tr>
</thead>
<tbody>
<tr>
<td>#ORD-4644</td>
<td>$510.95</td>
<td class="text-end"><button class="btn btn-sm btn-light border" type="button" data-ui-toggle="collapse" data-ui-target="#row-detail-920" aria-expanded="false" aria-controls="row-detail-920"><i class="bi bi-chevron-expand" aria-hidden="true"></i><span class="sr-only">Show details</span></button></td>
</tr>
<tr>
<td colspan="3" class="p-0 border-0"><div class="ui-collapse" id="row-detail-920"><div class="p-4 bg-surface-3 small">Billed to Samir Patel, Prague. Due Feb 8, 2027.</div></div></td>
</tr>
<tr>
<td>#INV-8527</td>
<td>$464.09</td>
<td class="text-end"><button class="btn btn-sm btn-light border" type="button" data-ui-toggle="collapse" data-ui-target="#row-detail-921" aria-expanded="false" aria-controls="row-detail-921"><i class="bi bi-chevron-expand" aria-hidden="true"></i><span class="sr-only">Show details</span></button></td>
</tr>
<tr>
<td colspan="3" class="p-0 border-0"><div class="ui-collapse" id="row-detail-921"><div class="p-4 bg-surface-3 small">Billed to Ava Carter, Auckland. Due Nov 26, 2026.</div></div></td>
</tr>
</tbody>
</table>
</div>9Advanced form options
Hide rarely used settings behind an "Advanced" toggle.
<div style="max-width: 420px;">
<a class="small" data-ui-toggle="collapse" href="#advanced-922" role="button" aria-expanded="false" aria-controls="advanced-922"><i class="bi bi-gear" aria-hidden="true"></i> Advanced options</a>
<div class="ui-collapse" id="advanced-922">
<div class="mt-2">
<label class="form-label small" for="adv-slug-923">URL slug</label>
<input class="form-control form-control-sm mb-2" id="adv-slug-923" type="text" value="a-beginner-s-guide-to-getting-started">
<div class="form-check">
<input class="form-check-input" type="checkbox" id="adv-index-924">
<label class="form-check-label small" for="adv-index-924">Hide from search engines</label>
</div>
</div>
</div>
</div>10Minimisable card
A header button collapses the card body, as in dashboard widgets.
<div class="card" style="max-width: 26rem;">
<div class="card-header flex justify-between items-center">
<span class="font-semibold"><i class="bi bi-graph-up" aria-hidden="true"></i> Traffic</span>
<button class="btn btn-sm btn-link link-secondary p-0" type="button" data-ui-toggle="collapse" data-ui-target="#widget-925" aria-expanded="true" aria-controls="widget-925"><i class="bi bi-dash-square" aria-hidden="true"></i><span class="sr-only">Minimise</span></button>
</div>
<div class="ui-collapse show" id="widget-925">
<div class="card-body">
<div class="text-2xl font-bold">
29.4k
</div>
<div class="small text-success-emphasis">
<i class="bi bi-arrow-up" aria-hidden="true"></i> 7% this week
</div>
</div>
</div>
</div>11Open by default
Add .show to start expanded; the button's aria-expanded is then true.
<button class="btn btn-outline-dark btn-sm" type="button" data-ui-toggle="collapse" data-ui-target="#collapse-926" aria-expanded="true" aria-controls="collapse-926">Hide summary</button>
<div class="ui-collapse show" id="collapse-926">
<div class="alert alert-secondary mt-2 mb-0">
Local partners know their communities and make sure help arrives where it matters. We keep things simple, so you can focus on what matters to you.
</div>
</div>12Rotating chevron
A chevron that turns when the panel opens, driven by aria-expanded in CSS.
<button class="btn btn-light border w-full flex justify-between items-center ca-chev" type="button" data-ui-toggle="collapse" data-ui-target="#collapse-927" aria-expanded="false" aria-controls="collapse-927" style="max-width: 420px;">Shipping & returns<i class="bi bi-chevron-down" aria-hidden="true"></i></button>
<div class="ui-collapse" id="collapse-927" style="max-width: 420px;">
<div class="p-4 small">
Clear prices, honest advice and no surprises along the way.
</div>
</div>13Comments thread
Keep a feed short and let readers open the replies.
Clean water wells are built with and maintained by local communities.
View 2 replies<p class="mb-1">Clean water wells are built with and maintained by local communities.</p>
<a class="small" data-ui-toggle="collapse" href="#comments-928" role="button" aria-expanded="false" aria-controls="comments-928"><i class="bi bi-chat" aria-hidden="true"></i> View 2 replies</a>
<div class="ui-collapse" id="comments-928">
<div class="mt-2 ps-4 border-s">
<div class="flex gap-2 mb-2">
<img src="../assets/img/avatar-2.svg" alt="Zoe Haddad" class="rounded-full shrink-0" width="32" height="32">
<div class="bg-surface-3 rounded-md p-2 small">
<strong>Zoe Haddad</strong> Thousands of donors already trust us, and we work hard to keep it that way.
</div>
</div>
<div class="flex gap-2 mb-2">
<img src="../assets/img/avatar-3.svg" alt="Diego Novak" class="rounded-full shrink-0" width="32" height="32">
<div class="bg-surface-3 rounded-md p-2 small">
<strong>Diego Novak</strong> Start in minutes and get help from a real person whenever you need it.
</div>
</div>
</div>
</div>14Release notes
A compact version line that expands into the full change list.
- Impact tracking
- Volunteer network
- Faster loading on slow connections
<div class="border rounded-md p-4">
<div class="flex justify-between items-center">
<div>
<span class="font-semibold">Version 5.5</span> <span class="badge text-bg-success">Stable</span>
<div class="small text-muted">
Feb 2, 2026
</div>
</div>
<button class="btn btn-outline-primary btn-sm" type="button" data-ui-toggle="collapse" data-ui-target="#notes-929" aria-expanded="false" aria-controls="notes-929">What's new</button>
</div>
<div class="ui-collapse" id="notes-929">
<ul class="small mt-4 mb-0">
<li>Impact tracking</li>
<li>Volunteer network</li>
<li>Faster loading on slow connections</li>
</ul>
</div>
</div>15Specification list
A definition list of technical details hidden behind a full-width toggle.
- Weight
- 7.1 kg
- Dimensions
- 58 x 46 x 12 cm
- Warranty
- 2 years
<button class="btn btn-outline-secondary w-full" type="button" data-ui-toggle="collapse" data-ui-target="#specs-930" aria-expanded="false" aria-controls="specs-930"><i class="bi bi-list-columns-reverse" aria-hidden="true"></i> Full specifications</button>
<div class="ui-collapse" id="specs-930">
<dl class="row small border rounded-md p-4 mt-2 mb-0">
<dt class="col-sm-4">Weight</dt>
<dd class="col-sm-8">7.1 kg</dd>
<dt class="col-sm-4">Dimensions</dt>
<dd class="col-sm-8">58 x 46 x 12 cm</dd>
<dt class="col-sm-4">Warranty</dt>
<dd class="col-sm-8 mb-0">2 years</dd>
</dl>
</div>16Expandable search bar
A search icon in a header opens a full-width search field below it.
<div class="border rounded-md">
<div class="flex items-center justify-between p-2">
<span class="font-bold">Glowia</span>
<button class="btn btn-light" type="button" data-ui-toggle="collapse" data-ui-target="#msearch-931" aria-expanded="false" aria-controls="msearch-931"><i class="bi bi-search" aria-hidden="true"></i><span class="sr-only">Search</span></button>
</div>
<div class="ui-collapse" id="msearch-931">
<div class="p-2 border-t">
<label class="sr-only" for="msearch-input-932">Search</label>
<input type="search" class="form-control" id="msearch-input-932" placeholder="Search Glowia">
</div>
</div>
</div>17Onboarding checklist
Each checklist step expands to explain what to do.
We listen first, then build a plan around what you actually need.
Every donation is tax-deductible, and receipts arrive by email instantly.
Our team has done this many times, so you never have to guess.
<div class="list-group" style="max-width: 480px;">
<div class="list-group-item">
<button class="btn btn-link p-0 no-underline link-body-emphasis flex items-center gap-2 w-full text-start" type="button" data-ui-toggle="collapse" data-ui-target="#step-933" aria-expanded="false" aria-controls="step-933"><span class="text-success-emphasis"><i class="bi bi-check-circle-fill" aria-hidden="true"></i></span>Verify your email</button>
<div class="ui-collapse" id="step-933">
<p class="small text-muted mt-2 mb-1 ms-6">We listen first, then build a plan around what you actually need.</p>
</div>
</div>
<div class="list-group-item">
<button class="btn btn-link p-0 no-underline link-body-emphasis flex items-center gap-2 w-full text-start" type="button" data-ui-toggle="collapse" data-ui-target="#step-934" aria-expanded="false" aria-controls="step-934"><span class="text-tertiary"><i class="bi bi-circle" aria-hidden="true"></i></span>Add a payment method</button>
<div class="ui-collapse" id="step-934">
<p class="small text-muted mt-2 mb-1 ms-6">Every donation is tax-deductible, and receipts arrive by email instantly.</p>
</div>
</div>
<div class="list-group-item">
<button class="btn btn-link p-0 no-underline link-body-emphasis flex items-center gap-2 w-full text-start" type="button" data-ui-toggle="collapse" data-ui-target="#step-935" aria-expanded="false" aria-controls="step-935"><span class="text-tertiary"><i class="bi bi-circle" aria-hidden="true"></i></span>Invite a teammate</button>
<div class="ui-collapse" id="step-935">
<p class="small text-muted mt-2 mb-1 ms-6">Our team has done this many times, so you never have to guess.</p>
</div>
</div>
</div>18Swap two panels
Two collapses sharing a class swap places: one hides while the other shows.
Read-only view: Companies can match employee donations and double their impact.
<div class="pane-group-938">
<div class="ui-collapse show pane-group-938-p" id="pane-936">
<div class="card card-body">
<p><i class="bi bi-eye" aria-hidden="true"></i> Read-only view: Companies can match employee donations and double their impact.</p>
<button class="btn btn-primary btn-sm self-start" type="button" data-ui-toggle="collapse" data-ui-target=".pane-group-938-p" aria-expanded="true" aria-controls="pane-936 pane-937"><i class="bi bi-pencil" aria-hidden="true"></i> Edit</button>
</div>
</div>
<div class="ui-collapse pane-group-938-p" id="pane-937">
<div class="card card-body">
<label class="form-label" for="pane-937-text">Description</label>
<textarea class="form-control mb-2" id="pane-937-text" rows="2">Our annual report is independently audited and published in full.</textarea>
<button class="btn btn-success btn-sm self-start" type="button" data-ui-toggle="collapse" data-ui-target=".pane-group-938-p" aria-expanded="false" aria-controls="pane-936 pane-937"><i class="bi bi-check-lg" aria-hidden="true"></i> Done</button>
</div>
</div>
</div>19Grouped notifications
Older notifications collapse into a single "show earlier" row.
- A school kit costs less than a cinema ticket and lasts a whole year.
- We have helped more than two hundred thousand people since we started.
- Every detail is handled by people who care about getting it right.
<ul class="list-group" style="max-width: 420px;">
<li class="list-group-item small"><i class="bi bi-bell" aria-hidden="true"></i> A school kit costs less than a cinema ticket and lasts a whole year.</li>
<li class="list-group-item p-0"><div class="ui-collapse" id="group-939"><ul class="list-group list-group-flush"><li class="list-group-item small text-muted">We have helped more than two hundred thousand people since we started.</li><li class="list-group-item small text-muted">Every detail is handled by people who care about getting it right.</li></ul></div><button class="btn btn-link btn-sm w-full" type="button" data-ui-toggle="collapse" data-ui-target="#group-939" aria-expanded="false" aria-controls="group-939">Show 9 earlier</button></li>
</ul>20Nested collapse
A collapse inside another for drilling into details step by step.
Ninety cents of every dollar goes directly to the projects you support.
- Design: $4,387.27
- Development: $13,217.57
- Marketing: $6,233.83
<button class="btn btn-outline-primary" type="button" data-ui-toggle="collapse" data-ui-target="#outer-940" aria-expanded="false" aria-controls="outer-940">Project details</button>
<div class="ui-collapse" id="outer-940">
<div class="card card-body mt-2">
<p>Ninety cents of every dollar goes directly to the projects you support.</p>
<button class="btn btn-sm btn-outline-secondary self-start" type="button" data-ui-toggle="collapse" data-ui-target="#inner-941" aria-expanded="false" aria-controls="inner-941">Budget breakdown</button>
<div class="ui-collapse" id="inner-941">
<ul class="small mt-2 mb-0">
<li>Design: $4,387.27</li>
<li>Development: $13,217.57</li>
<li>Marketing: $6,233.83</li>
</ul>
</div>
</div>
</div>