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Bootstrap/site/content/docs/5.1/components/navbar.md
Julien Déramond 31998dfd1e
Fix spacing utility classes mentioned in navbar supported content documentation (#35328) 
Co-authored-by: XhmikosR <xhmikosr@gmail.com>
2021-11-05 20:36:56 +02:00

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docs Navbar Documentation and examples for Bootstrap's powerful, responsive navigation header, the navbar. Includes support for branding, navigation, and more, including support for our collapse plugin. components true

How it works

Here's what you need to know before getting started with the navbar:

  • Navbars require a wrapping .navbar with .navbar-expand{-sm|-md|-lg|-xl|-xxl} for responsive collapsing and color scheme classes.
  • Navbars and their contents are fluid by default. Change the container to limit their horizontal width in different ways.
  • Use our [spacing]({{< docsref "/utilities/spacing" >}}) and [flex]({{< docsref "/utilities/flex" >}}) utility classes for controlling spacing and alignment within navbars.
  • Navbars are responsive by default, but you can easily modify them to change that. Responsive behavior depends on our Collapse JavaScript plugin.
  • Ensure accessibility by using a <nav> element or, if using a more generic element such as a <div>, add a role="navigation" to every navbar to explicitly identify it as a landmark region for users of assistive technologies.
  • Indicate the current item by using aria-current="page" for the current page or aria-current="true" for the current item in a set.

{{< callout info >}} {{< partial "callout-info-prefersreducedmotion.md" >}} {{< /callout >}}

Supported content

Navbars come with built-in support for a handful of sub-components. Choose from the following as needed:

  • .navbar-brand for your company, product, or project name.
  • .navbar-nav for a full-height and lightweight navigation (including support for dropdowns).
  • .navbar-toggler for use with our collapse plugin and other navigation toggling behaviors.
  • Flex and spacing utilities for any form controls and actions.
  • .navbar-text for adding vertically centered strings of text.
  • .collapse.navbar-collapse for grouping and hiding navbar contents by a parent breakpoint.
  • Add an optional .navbar-scroll to set a max-height and scroll expanded navbar content.

Here's an example of all the sub-components included in a responsive light-themed navbar that automatically collapses at the lg (large) breakpoint.

{{< example >}}

{{< /example >}}

This example uses [background]({{< docsref "/utilities/background" >}}) (bg-light) and [spacing]({{< docsref "/utilities/spacing" >}}) (me-auto, mb-2, mb-lg-0, me-2) utility classes.

Brand

The .navbar-brand can be applied to most elements, but an anchor works best, as some elements might require utility classes or custom styles.

Text

Add your text within an element with the .navbar-brand class.

{{< example >}}

Navbar
{{< /example >}}

Image

You can replace the text within the .navbar-brand with an <img>.

{{< example >}}

{{< /example >}}

Image and text

You can also make use of some additional utilities to add an image and text at the same time. Note the addition of .d-inline-block and .align-text-top on the <img>.

{{< example >}}

{{< /example >}}

Nav

Navbar navigation links build on our .nav options with their own modifier class and require the use of toggler classes for proper responsive styling. Navigation in navbars will also grow to occupy as much horizontal space as possible to keep your navbar contents securely aligned.

Add the .active class on .nav-link to indicate the current page.

Please note that you should also add the aria-current attribute on the active .nav-link.

{{< example >}}

{{< /example >}}

And because we use classes for our navs, you can avoid the list-based approach entirely if you like.

{{< example >}}

{{< /example >}}

You can also use dropdowns in your navbar. Dropdown menus require a wrapping element for positioning, so be sure to use separate and nested elements for .nav-item and .nav-link as shown below.

{{< example >}}

{{< /example >}}

Forms

Place various form controls and components within a navbar:

{{< example >}}

Search
{{< /example >}}

Immediate child elements of .navbar use flex layout and will default to justify-content: space-between. Use additional [flex utilities]({{< docsref "/utilities/flex" >}}) as needed to adjust this behavior.

{{< example >}}

Navbar Search
{{< /example >}}

Input groups work, too. If your navbar is an entire form, or mostly a form, you can use the <form> element as the container and save some HTML.

{{< example >}}

@
{{< /example >}}

Various buttons are supported as part of these navbar forms, too. This is also a great reminder that vertical alignment utilities can be used to align different sized elements.

{{< example >}}

Main button Smaller button {{< /example >}}

Text

Navbars may contain bits of text with the help of .navbar-text. This class adjusts vertical alignment and horizontal spacing for strings of text.

{{< example >}}

Navbar text with an inline element
{{< /example >}}

Mix and match with other components and utilities as needed.

{{< example >}}

Navbar w/ text
Navbar text with an inline element
{{< /example >}}

Color schemes

Theming the navbar has never been easier thanks to the combination of theming classes and background-color utilities. Choose from .navbar-light for use with light background colors, or .navbar-dark for dark background colors. Then, customize with .bg-* utilities.

<nav class="navbar navbar-dark bg-dark">
  <!-- Navbar content -->
</nav>

<nav class="navbar navbar-dark bg-primary">
  <!-- Navbar content -->
</nav>

<nav class="navbar navbar-light" style="background-color: #e3f2fd;">
  <!-- Navbar content -->
</nav>

Containers

Although it's not required, you can wrap a navbar in a .container to center it on a page–though note that an inner container is still required. Or you can add a container inside the .navbar to only center the contents of a fixed or static top navbar.

{{< example >}}

{{< /example >}}

Use any of the responsive containers to change how wide the content in your navbar is presented.

{{< example >}}

{{< /example >}}

Placement

Use our [position utilities]({{< docsref "/utilities/position" >}}) to place navbars in non-static positions. Choose from fixed to the top, fixed to the bottom, or stickied to the top (scrolls with the page until it reaches the top, then stays there). Fixed navbars use position: fixed, meaning they're pulled from the normal flow of the DOM and may require custom CSS (e.g., padding-top on the <body>) to prevent overlap with other elements.

Also note that .sticky-top uses position: sticky, which isn't fully supported in every browser.

{{< example >}}

{{< /example >}}

{{< example >}}

{{< /example >}}

{{< example >}}

{{< /example >}}

{{< example >}}

{{< /example >}}

Scrolling

Add .navbar-nav-scroll to a .navbar-nav (or other navbar sub-component) to enable vertical scrolling within the toggleable contents of a collapsed navbar. By default, scrolling kicks in at 75vh (or 75% of the viewport height), but you can override that with the local CSS custom property --bs-navbar-height or custom styles. At larger viewports when the navbar is expanded, content will appear as it does in a default navbar.

Please note that this behavior comes with a potential drawback of overflow—when setting overflow-y: auto (required to scroll the content here), overflow-x is the equivalent of auto, which will crop some horizontal content.

Here's an example navbar using .navbar-nav-scroll with style="--bs-scroll-height: 100px;", with some extra margin utilities for optimum spacing.

{{< example >}}

{{< /example >}}

Responsive behaviors

Navbars can use .navbar-toggler, .navbar-collapse, and .navbar-expand{-sm|-md|-lg|-xl|-xxl} classes to determine when their content collapses behind a button. In combination with other utilities, you can easily choose when to show or hide particular elements.

For navbars that never collapse, add the .navbar-expand class on the navbar. For navbars that always collapse, don't add any .navbar-expand class.

Toggler

Navbar togglers are left-aligned by default, but should they follow a sibling element like a .navbar-brand, they'll automatically be aligned to the far right. Reversing your markup will reverse the placement of the toggler. Below are examples of different toggle styles.

With no .navbar-brand shown at the smallest breakpoint:

{{< example >}}

Hidden brand Search
{{< /example >}}

With a brand name shown on the left and toggler on the right:

{{< example >}}

Navbar
Search
{{< /example >}}

With a toggler on the left and brand name on the right:

{{< example >}}

Navbar
Search
{{< /example >}}

External content

Sometimes you want to use the collapse plugin to trigger a container element for content that structurally sits outside of the .navbar . Because our plugin works on the id and data-bs-target matching, that's easily done!

{{< example >}}

Collapsed content
Toggleable via the navbar brand.
{{< /example >}}

When you do this, we recommend including additional JavaScript to move the focus programmatically to the container when it is opened. Otherwise, keyboard users and users of assistive technologies will likely have a hard time finding the newly revealed content - particularly if the container that was opened comes before the toggler in the document's structure. We also recommend making sure that the toggler has the aria-controls attribute, pointing to the id of the content container. In theory, this allows assistive technology users to jump directly from the toggler to the container it controls–but support for this is currently quite patchy.

Offcanvas

Transform your expanding and collapsing navbar into an offcanvas drawer with the offcanvas plugin. We extend both the offcanvas default styles and use our .navbar-expand-* classes to create a dynamic and flexible navigation sidebar.

In the example below, to create an offcanvas navbar that is always collapsed across all breakpoints, omit the .navbar-expand-* class entirely.

{{< example >}}

{{< /example >}}

To create an offcanvas navbar that expands into a normal navbar at a specific breakpoint like lg, use .navbar-expand-lg.

<nav class="navbar navbar-light navbar-expand-lg bg-light fixed-top">
  <a class="navbar-brand" href="#">Offcanvas navbar</a>
  <button class="navbar-toggler" type="button" data-bs-toggle="offcanvas" data-bs-target="#navbarOffcanvasLg" aria-controls="navbarOffcanvasLg">
    <span class="navbar-toggler-icon"></span>
  </button>
  <div class="offcanvas offcanvas-end" tabindex="-1" id="navbarOffcanvasLg" aria-labelledby="navbarOffcanvasLgLabel">
    ...
  </div>
</nav>

Sass

Variables

{{< scss-docs name="navbar-variables" file="scss/_variables.scss" >}}

{{< scss-docs name="navbar-theme-variables" file="scss/_variables.scss" >}}

Loop

Responsive navbar expand/collapse classes (e.g., .navbar-expand-lg) are combined with the $breakpoints map and generated through a loop in scss/_navbar.scss.

{{< scss-docs name="navbar-expand-loop" file="scss/_navbar.scss" >}}