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="collapse" id="collapse-908">
<div class="card card-body mt-2">
Every detail is handled by people who care about getting it right. Start in minutes and get help from a real person whenever you need it.
</div>
</div>2Link toggle
A link with href="#id" and role="button" works the same way.
Pay securely with card, wallet or in three interest-free instalments.
<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="collapse" id="collapse-909">
<p class="small text-body-secondary mt-2 mb-0">Pay securely with card, wallet or in three interest-free instalments.</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="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="d-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="collapse multi-group-913" id="multi-911">
<div class="card card-body">
Our packaging is plastic-free and every delivery is carbon-neutral.
</div>
</div>
</div>
<div class="col-sm-6">
<div class="collapse multi-group-913" id="multi-912">
<div class="card card-body">
Clear prices, honest advice and no surprises along the way.
</div>
</div>
</div>
</div>5Read more
Show the first part of a text and reveal the rest on demand.
Members get early access to new drops and prices only they can see. Friendly people answer your questions quickly, by phone, chat or email.
We measure success by how many shoppers come back and tell their friends. Our team has done this many times, so you never have to guess. Clear prices, honest advice and no surprises along the way.
<p class="mb-1">Members get early access to new drops and prices only they can see. Friendly people answer your questions quickly, by phone, chat or email.</p>
<div class="collapse" id="more-914">
<p class="mb-1">We measure success by how many shoppers come back and tell their friends. Our team has done this many times, so you never have to guess. Clear prices, honest advice and no surprises along the way.</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="d-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="collapse" id="filters-915">
<div class="border rounded p-3 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="Kai Lindqvist">
</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 p-2" style="max-width: 260px;" aria-label="Admin menu">
<ul class="nav flex-column">
<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 d-flex justify-content-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="collapse show" id="menu-918"><ul class="nav flex-column ms-4 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 d-flex justify-content-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="collapse" id="menu-919"><ul class="nav flex-column ms-4 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 |
|---|---|---|
| #TX-4871 | $816.78 | |
Billed to Zoe Rossi, Barcelona. Due Nov 14, 2026. | ||
| #PO-2508 | $816.67 | |
Billed to Leo Kowalski, Montreal. Due Dec 23, 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="visually-hidden">Details</span></th>
</tr>
</thead>
<tbody>
<tr>
<td>#TX-4871</td>
<td>$816.78</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="visually-hidden">Show details</span></button></td>
</tr>
<tr>
<td colspan="3" class="p-0 border-0"><div class="collapse" id="row-detail-920"><div class="p-3 bg-body-tertiary small">Billed to Zoe Rossi, Barcelona. Due Nov 14, 2026.</div></div></td>
</tr>
<tr>
<td>#PO-2508</td>
<td>$816.67</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="visually-hidden">Show details</span></button></td>
</tr>
<tr>
<td colspan="3" class="p-0 border-0"><div class="collapse" id="row-detail-921"><div class="p-3 bg-body-tertiary small">Billed to Leo Kowalski, Montreal. Due Dec 23, 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="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="five-things-we-learned-this-year">
<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 d-flex justify-content-between align-items-center">
<span class="fw-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="visually-hidden">Minimise</span></button>
</div>
<div class="collapse show" id="widget-925">
<div class="card-body">
<div class="fs-3 fw-bold">
46.1k
</div>
<div class="small text-success">
<i class="bi bi-arrow-up" aria-hidden="true"></i> 16% 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="collapse show" id="collapse-926">
<div class="alert alert-secondary mt-2 mb-0">
Every detail is handled by people who care about getting it right. Free shipping on orders over $50 and easy returns within 30 days.
</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-100 d-flex justify-content-between align-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="collapse" id="collapse-927" style="max-width: 420px;">
<div class="p-3 small">
New pieces arrive every month, and the best ones sell out fast.
</div>
</div>13Comments thread
Keep a feed short and let readers open the replies.
Pay securely with card, wallet or in three interest-free instalments.
View 2 replies<p class="mb-1">Pay securely with card, wallet or in three interest-free instalments.</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="collapse" id="comments-928">
<div class="mt-2 ps-3 border-start">
<div class="d-flex gap-2 mb-2">
<img src="../assets/img/avatar-2.svg" alt="Owen Quinn" class="rounded-circle flex-shrink-0" width="32" height="32">
<div class="bg-body-tertiary rounded p-2 small">
<strong>Owen Quinn</strong> Order before 2 pm and most items leave our warehouse the same day.
</div>
</div>
<div class="d-flex gap-2 mb-2">
<img src="../assets/img/avatar-4.svg" alt="Nadia Harlow" class="rounded-circle flex-shrink-0" width="32" height="32">
<div class="bg-body-tertiary rounded p-2 small">
<strong>Nadia Harlow</strong> We listen first, then build a plan around what you actually need.
</div>
</div>
</div>
</div>14Release notes
A compact version line that expands into the full change list.
- Carbon-neutral delivery
- Member prices
- Faster loading on slow connections
<div class="border rounded p-3">
<div class="d-flex justify-content-between align-items-center">
<div>
<span class="fw-semibold">Version 3.9</span> <span class="badge text-bg-success">Stable</span>
<div class="small text-body-secondary">
Aug 28, 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="collapse" id="notes-929">
<ul class="small mt-3 mb-0">
<li>Carbon-neutral delivery</li>
<li>Member prices</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
- 5.3 kg
- Dimensions
- 49 x 31 x 16 cm
- Warranty
- 2 years
<button class="btn btn-outline-secondary w-100" 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="collapse" id="specs-930">
<dl class="row small border rounded p-3 mt-2 mb-0">
<dt class="col-sm-4">Weight</dt>
<dd class="col-sm-8">5.3 kg</dd>
<dt class="col-sm-4">Dimensions</dt>
<dd class="col-sm-8">49 x 31 x 16 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">
<div class="d-flex align-items-center justify-content-between p-2">
<span class="fw-bold">Emberium Deck</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="visually-hidden">Search</span></button>
</div>
<div class="collapse" id="msearch-931">
<div class="p-2 border-top">
<label class="visually-hidden" for="msearch-input-932">Search</label>
<input type="search" class="form-control" id="msearch-input-932" placeholder="Search Emberium Deck">
</div>
</div>
</div>17Onboarding checklist
Each checklist step expands to explain what to do.
Our packaging is plastic-free and every delivery is carbon-neutral.
Thousands of shoppers already trust us, and we work hard to keep it that way.
Thousands of five-star reviews from customers who came back for more.
<div class="list-group" style="max-width: 480px;">
<div class="list-group-item">
<button class="btn btn-link p-0 text-decoration-none link-body-emphasis d-flex align-items-center gap-2 w-100 text-start" type="button" data-ui-toggle="collapse" data-ui-target="#step-933" aria-expanded="false" aria-controls="step-933"><span class="text-success"><i class="bi bi-check-circle-fill" aria-hidden="true"></i></span>Verify your email</button>
<div class="collapse" id="step-933">
<p class="small text-body-secondary mt-2 mb-1 ms-4">Our packaging is plastic-free and every delivery is carbon-neutral.</p>
</div>
</div>
<div class="list-group-item">
<button class="btn btn-link p-0 text-decoration-none link-body-emphasis d-flex align-items-center gap-2 w-100 text-start" type="button" data-ui-toggle="collapse" data-ui-target="#step-934" aria-expanded="false" aria-controls="step-934"><span class="text-body-tertiary"><i class="bi bi-circle" aria-hidden="true"></i></span>Add a payment method</button>
<div class="collapse" id="step-934">
<p class="small text-body-secondary mt-2 mb-1 ms-4">Thousands of shoppers already trust us, and we work hard to keep it that way.</p>
</div>
</div>
<div class="list-group-item">
<button class="btn btn-link p-0 text-decoration-none link-body-emphasis d-flex align-items-center gap-2 w-100 text-start" type="button" data-ui-toggle="collapse" data-ui-target="#step-935" aria-expanded="false" aria-controls="step-935"><span class="text-body-tertiary"><i class="bi bi-circle" aria-hidden="true"></i></span>Invite a teammate</button>
<div class="collapse" id="step-935">
<p class="small text-body-secondary mt-2 mb-1 ms-4">Thousands of five-star reviews from customers who came back for more.</p>
</div>
</div>
</div>18Swap two panels
Two collapses sharing a class swap places: one hides while the other shows.
Read-only view: Every piece is made in small batches from materials we test ourselves.
<div class="pane-group-938">
<div class="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: Every piece is made in small batches from materials we test ourselves.</p>
<button class="btn btn-primary btn-sm align-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="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">Not sure about the size? Our fit guide and live chat help you choose.</textarea>
<button class="btn btn-success btn-sm align-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.
- Members get early access to new drops and prices only they can see.
- We work directly with makers, so prices stay fair for everyone.
- Start in minutes and get help from a real person whenever you need it.
<ul class="list-group" style="max-width: 420px;">
<li class="list-group-item small"><i class="bi bi-bell" aria-hidden="true"></i> Members get early access to new drops and prices only they can see.</li>
<li class="list-group-item p-0"><div class="collapse" id="group-939"><ul class="list-group list-group-flush"><li class="list-group-item small text-body-secondary">We work directly with makers, so prices stay fair for everyone.</li><li class="list-group-item small text-body-secondary">Start in minutes and get help from a real person whenever you need it.</li></ul></div><button class="btn btn-link btn-sm w-100" type="button" data-ui-toggle="collapse" data-ui-target="#group-939" aria-expanded="false" aria-controls="group-939">Show 7 earlier</button></li>
</ul>20Nested collapse
A collapse inside another for drilling into details step by step.
Gift wrapping and a handwritten note are free on every order.
- Design: $1,987.63
- Development: $7,933.58
- Marketing: $7,749.02
<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="collapse" id="outer-940">
<div class="card card-body mt-2">
<p>Gift wrapping and a handwritten note are free on every order.</p>
<button class="btn btn-sm btn-outline-secondary align-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="collapse" id="inner-941">
<ul class="small mt-2 mb-0">
<li>Design: $1,987.63</li>
<li>Development: $7,933.58</li>
<li>Marketing: $7,749.02</li>
</ul>
</div>
</div>
</div>