Collapse shows and hides content with a short animation. Point a button or link at the target with data-bs-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-bs-toggle="collapse" shows and hides the target.
Start in minutes and get help from a real person whenever you need it. Short quizzes after each lesson help new knowledge stick.
<button class="btn btn-primary" type="button" data-bs-toggle="collapse" data-bs-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">
Start in minutes and get help from a real person whenever you need it. Short quizzes after each lesson help new knowledge stick.
</div>
</div>2Link toggle
A link with href="#id" and role="button" works the same way.
What does this mean?
Every course is built around hands-on projects you can add to your portfolio.
<a class="link-primary" data-bs-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">Every course is built around hands-on projects you can add to your portfolio.</p>
</div>3Horizontal collapse
collapse-horizontal animates the width; the content needs a fixed width.
Instructors are working professionals who teach what they use every day.
<button class="btn btn-outline-primary" type="button" data-bs-toggle="collapse" data-bs-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;">
Instructors are working professionals who teach what they use every day.
</div>
</div>
</div>4Multiple targets
One button can toggle several elements by targeting a shared class.
The mobile app downloads lessons, so you can learn on the train.
Friendly people answer your questions quickly, by phone, chat or email.
<div class="d-flex flex-wrap gap-2 mb-2">
<button class="btn btn-outline-secondary" type="button" data-bs-toggle="collapse" data-bs-target="#multi-911" aria-expanded="false" aria-controls="multi-911">Toggle first</button>
<button class="btn btn-outline-secondary" type="button" data-bs-toggle="collapse" data-bs-target="#multi-912" aria-expanded="false" aria-controls="multi-912">Toggle second</button>
<button class="btn btn-primary" type="button" data-bs-toggle="collapse" data-bs-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">
The mobile app downloads lessons, so you can learn on the train.
</div>
</div>
</div>
<div class="col-sm-6">
<div class="collapse multi-group-913" id="multi-912">
<div class="card card-body">
Friendly people answer your questions quickly, by phone, chat or email.
</div>
</div>
</div>
</div>5Read more
Show the first part of a text and reveal the rest on demand.
Lifetime access means you can revisit lessons whenever you need a refresher. Career coaches help with your CV, portfolio and interview practice.
We keep things simple, so you can focus on what matters to you. Mentors review your projects and give feedback within two days. Every course is built around hands-on projects you can add to your portfolio.
<p class="mb-1">Lifetime access means you can revisit lessons whenever you need a refresher. Career coaches help with your CV, portfolio and interview practice.</p>
<div class="collapse" id="more-914">
<p class="mb-1">We keep things simple, so you can focus on what matters to you. Mentors review your projects and give feedback within two days. Every course is built around hands-on projects you can add to your portfolio.</p>
</div>
<button class="btn btn-link px-0 ca-more" type="button" data-bs-toggle="collapse" data-bs-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-bs-toggle="collapse" data-bs-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="Ivy Hughes">
</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-bs-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-bs-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-3224 | $629.75 | |
Billed to Nora Novak, Dublin. Due Dec 25, 2026. | ||
| #PO-7984 | $613.74 | |
Billed to Priya Fischer, Lisbon. Due Nov 4, 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-3224</td>
<td>$629.75</td>
<td class="text-end"><button class="btn btn-sm btn-light border" type="button" data-bs-toggle="collapse" data-bs-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 Nora Novak, Dublin. Due Dec 25, 2026.</div></div></td>
</tr>
<tr>
<td>#PO-7984</td>
<td>$613.74</td>
<td class="text-end"><button class="btn btn-sm btn-light border" type="button" data-bs-toggle="collapse" data-bs-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 Priya Fischer, Lisbon. Due Nov 4, 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-bs-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="our-most-popular-courses-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.
Traffic
67.3k
10% this week
<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-bs-toggle="collapse" data-bs-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">
67.3k
</div>
<div class="small text-success">
<i class="bi bi-arrow-up" aria-hidden="true"></i> 10% this week
</div>
</div>
</div>
</div>11Open by default
Add .show to start expanded; the button's aria-expanded is then true.
We keep things simple, so you can focus on what matters to you. Clear prices, honest advice and no surprises along the way.
<button class="btn btn-outline-dark btn-sm" type="button" data-bs-toggle="collapse" data-bs-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">
We keep things simple, so you can focus on what matters to you. Clear prices, honest advice and no surprises along the way.
</div>
</div>12Rotating chevron
A chevron that turns when the panel opens, driven by aria-expanded in CSS.
We measure success by how many students come back and tell their friends.
<button class="btn btn-light border w-100 d-flex justify-content-between align-items-center ca-chev" type="button" data-bs-toggle="collapse" data-bs-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">
We measure success by how many students come back and tell their friends.
</div>
</div>13Comments thread
Keep a feed short and let readers open the replies.
Learn on your schedule, with lessons that fit into a lunch break.
View 2 replies
Ava Lindqvist Instructors are working professionals who teach what they use every day.
Nadia Tanaka Study groups and a friendly forum keep you motivated along the way.
<p class="mb-1">Learn on your schedule, with lessons that fit into a lunch break.</p>
<a class="small" data-bs-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-7.svg" alt="Ava Lindqvist" class="rounded-circle flex-shrink-0" width="32" height="32">
<div class="bg-body-tertiary rounded p-2 small">
<strong>Ava Lindqvist</strong> Instructors are working professionals who teach what they use every day.
</div>
</div>
<div class="d-flex gap-2 mb-2">
<img src="../assets/img/avatar-11.svg" alt="Nadia Tanaka" class="rounded-circle flex-shrink-0" width="32" height="32">
<div class="bg-body-tertiary rounded p-2 small">
<strong>Nadia Tanaka</strong> Study groups and a friendly forum keep you motivated along the way.
</div>
</div>
</div>
</div>14Release notes
A compact version line that expands into the full change list.
Version 4.7 Stable
Oct 8, 2025
- Lifetime access
- Community forum
- 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 4.7</span> <span class="badge text-bg-success">Stable</span>
<div class="small text-body-secondary">
Oct 8, 2025
</div>
</div>
<button class="btn btn-outline-primary btn-sm" type="button" data-bs-toggle="collapse" data-bs-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>Lifetime access</li>
<li>Community forum</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
- 5.5 kg
- Dimensions
- 55 x 31 x 5 cm
- Warranty
- 1 years
<button class="btn btn-outline-secondary w-100" type="button" data-bs-toggle="collapse" data-bs-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">5.5 kg</dd>
<dt class="col-sm-4">Dimensions</dt>
<dd class="col-sm-8">55 x 31 x 5 cm</dd>
<dt class="col-sm-4">Warranty</dt>
<dd class="col-sm-8 mb-0">1 years</dd>
</dl>
</div>16Expandable search bar
A search icon in a header opens a full-width search field below it.
Haloara Kit
<div class="border rounded">
<div class="d-flex align-items-center justify-content-between p-2">
<span class="fw-bold">Haloara Kit</span>
<button class="btn btn-light" type="button" data-bs-toggle="collapse" data-bs-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 Haloara Kit">
</div>
</div>
</div>17Onboarding checklist
Each checklist step expands to explain what to do.
Friendly people answer your questions quickly, by phone, chat or email.
Guided learning paths take you from beginner to job-ready step by step.
We listen first, then build a plan around what you actually need.
<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-bs-toggle="collapse" data-bs-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">Friendly people answer your questions quickly, by phone, chat or email.</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-bs-toggle="collapse" data-bs-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">Guided learning paths take you from beginner to job-ready step by step.</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-bs-toggle="collapse" data-bs-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">We listen first, then build a plan around what you actually need.</p>
</div>
</div>
</div>18Swap two panels
Two collapses sharing a class swap places: one hides while the other shows.
Read-only view: The mobile app downloads lessons, so you can learn on the train.
<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: The mobile app downloads lessons, so you can learn on the train.</p>
<button class="btn btn-primary btn-sm align-self-start" type="button" data-bs-toggle="collapse" data-bs-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">Lifetime access means you can revisit lessons whenever you need a refresher.</textarea>
<button class="btn btn-success btn-sm align-self-start" type="button" data-bs-toggle="collapse" data-bs-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.
- Every detail is handled by people who care about getting it right.
- Thousands of students already trust us, and we work hard to keep it that way.
- 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> Every detail is handled by people who care about getting it right.</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">Thousands of students already trust us, and we work hard to keep it that way.</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-bs-toggle="collapse" data-bs-target="#group-939" aria-expanded="false" aria-controls="group-939">Show 4 earlier</button></li>
</ul>20Nested collapse
A collapse inside another for drilling into details step by step.
Our team has done this many times, so you never have to guess.
- Design: $2,851.13
- Development: $19,814.71
- Marketing: $2,747.80
<button class="btn btn-outline-primary" type="button" data-bs-toggle="collapse" data-bs-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>Our team has done this many times, so you never have to guess.</p>
<button class="btn btn-sm btn-outline-secondary align-self-start" type="button" data-bs-toggle="collapse" data-bs-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: $2,851.13</li>
<li>Development: $19,814.71</li>
<li>Marketing: $2,747.80</li>
</ul>
</div>
</div>
</div>