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Bootstrap 4 Utilities


Bootstrap 4 Utilities

Bootstrap 4 has alot of utility/helper classes to quickly style elements without using any CSS code.


Borders

Use the border classes to add or remove borders from an element:

Example

Example

<span class="border"></span>
<span class="border border-0"></span>
<span class="border border-top-0"></span>
<span class="border border-right-0"></span>
<span class="border border-bottom-0"></span>
<span class="border border-left-0"></span>
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Border Color

Add a color to the border with any of the contextual border color classes:

Example

Example

<span class="border border-primary"></span>
<span class="border border-secondary"></span>
<span class="border border-success"></span>
<span class="border border-danger"></span>
<span class="border border-warning"></span>
<span class="border border-info"></span>
<span class="border border-light"></span>
<span class="border border-dark"></span>
<span class="border border-white"></span>
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Border Radius

Add rounded corners to an element with the rounded classes:

Example

Example

<span class="rounded"></span>
<span class="rounded-top"></span>
<span class="rounded-right"></span>
<span class="rounded-bottom"></span>
<span class="rounded-left"></span>
<span class="rounded-circle"></span>
<span class="rounded-0"></span>
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Float and Clearfix

Float an element to the right with the .float-right class or to the left with .float-left, and clear floats with the .clearfix class:

Example

Float left Float right

Example

<div class="clearfix">
  <span class="float-left">Float left</span>
  <span class="float-right">Float right</span>
</div>
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Responsive Floats

Float an element to the left or to the right depending on screen width, with the responsive float classes (.float-*-left|right - where * is sm (>=576px), md (>=768px), lg (>=992px) or xl (>=1200px)):

Example

Float right on small screens or wider

Float right on medium screens or wider

Float right on large screens or wider

Float right on extra large screens or wider

Float none

Example

<div class="float-sm-right">Float right on small screens or wider</div><br>
<div class="float-md-right">Float right on medium screens or wider</div><br>
<div class="float-lg-right">Float right on large screens or wider</div><br>
<div class="float-xl-right">Float right on extra large screens or wider</div><br>
<div class="float-none">Float none</div>
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Center Align

Center an element with the .mx-auto class (adds margin-left and margin-right: auto):

Example

Centered

Example

<div class="mx-auto bg-warning" style="width:150px">Centered</div>
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Width

Set the width of an element with the w-* classes (.w-25, .w-50, .w-75, .w-100, .mw-100):

Example

Width 25%
Width 50%
Width 75%
Width 100%
Max Width 100%

Example

<div class="w-25 bg-warning">Width 25%</div>
<div class="w-50 bg-warning">Width 50%</div>
<div class="w-75 bg-warning">Width 75%</div>
<div class="w-100 bg-warning">Width 100%</div>
<div class="mw-100 bg-warning">Max Width 100%</div>
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Height

Set the height of an element with the h-* classes (.h-25, .h-50, .h-75, .h-100, .mh-100):

Example

Height 25%
Height 50%
Height 75%
Height 100%
Max Height 100%

Example

<div style="height:200px;background-color:#ddd">
  <div class="h-25 bg-warning">Height 25%</div>
  <div class="h-50 bg-warning">Height 50%</div>
  <div class="h-75 bg-warning">Height 75%</div>
  <div class="h-100 bg-warning">Height 100%</div>
  <div class="mh-100 bg-warning" style="height:500px">Max Height 100%</div>
</div>
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Spacing

Bootstrap 4 has a wide range of responsive margin and padding utility classes. They work for all breakpoints: xs (<=576px), sm (>=576px), md (>=768px), lg (>=992px) or xl (>=1200px)):

The classes are used in the format: {property}{sides}-{size} for xs and {property}{sides}-{breakpoint}-{size} for sm, md, lg, and xl.

Where property is one of:

  • m - sets margin
  • p - sets padding

Where sides is one of:

  • t - sets margin-top or padding-top
  • b - sets margin-bottom or padding-bottom
  • l - sets margin-left or padding-left
  • r - sets margin-right or padding-right
  • x - sets both padding-left and padding-right or margin-left and margin-right
  • y - sets both padding-top and padding-bottom or margin-top and margin-bottom
  • blank - sets a margin or padding on all 4 sides of the element

Where size is one of:

  • 0 - sets margin or padding to 0
  • 1 - sets margin or padding to .25rem (4px if font-size is 16px)
  • 2 - sets margin or padding to .5rem (8px if font-size is 16px)
  • 3 - sets margin or padding to 1rem (16px if font-size is 16px)
  • 4 - sets margin or padding to 1.5rem (24px if font-size is 16px)
  • 5 - sets margin or padding to 3rem (48px if font-size is 16px)
  • auto - sets margin to auto

Example

I only have a top padding (1.5rem = 24px)
I have a padding on all sides (3rem = 48px)
I have a margin on all sides (3rem = 48px) and a bottom padding (3rem = 48px)

Example

<div class="pt-4 bg-warning">I only have a top padding (1.5rem = 24px)</div>
<div class="p-5 bg-success">I have a padding on all sides (3rem = 48px)</div>
<div class="m-5 pb-5 bg-info">I have a margin on all sides (3rem = 48px) and a bottom padding (3rem = 48px)</div>
Try it Yourself »

More Spacing Examples

.m-# / m-*-# margin on all sides Try it
.mt-# / mt-*-# margin top Try it
.mb-# / mb-*-# margin bottom Try it
.ml-# / ml-*-# margin left Try it
.mr-# / mr-*-# margin right Try it
.mx-# / mx-*-# margin left and right Try it
.my-# / my-*-# margin top and bottom Try it
.p-# / p-*-# padding on all sides Try it
.pt-# / pt-*-# padding top Try it
.pb-# / pb-*-# padding bottom Try it
.pl-# / pl-*-# padding left Try it
.pr-# / pr-*-# padding right Try it
.py-# / py-*-# padding top and bottom Try it
.px-# / px-*-# padding left and right Try it

Shadows

Use the shadow- classes to to add shadows to an element:

Example

No shadow
Small shadow
Default shadow
Large shadow

Example

<div class="shadow-none p-4 mb-4 bg-light">No shadow</div>
<div class="shadow-sm p-4 mb-4 bg-white">Small shadow</div>
<div class="shadow p-4 mb-4 bg-white">Default shadow</div>
<div class="shadow-lg p-4 mb-4 bg-white">Large shadow</div>
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Vertical Align

Use the align- classes to change the alignment of elements (only works on inline, inline-block, inline-table and table cell elements):

Example

baseline top middle bottom text-top text-bottom

Example

<span class="align-baseline">baseline</span>
<span class="align-top">top</span>
<span class="align-middle">middle</span>
<span class="align-bottom">bottom</span>
<span class="align-text-top">text-top</span>
<span class="align-text-bottom">text-bottom</span>
Try it Yourself »

Responsive Embeds

Create responsive video or slideshow embeds based on the width of the parent.

Add the .embed-responsive-item to any embed elements (like <iframe> or <video>) in a parent element with .embed-responsive and an aspect ratio of your choice:

Example

Example

<!-- 21:9 aspect ratio -->
<div class="embed-responsive embed-responsive-21by9">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

<!-- 16:9 aspect ratio -->
<div class="embed-responsive embed-responsive-16by9">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

<!-- 4:3 aspect ratio -->
<div class="embed-responsive embed-responsive-4by3">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

<!-- 1:1 aspect ratio -->
<div class="embed-responsive embed-responsive-1by1">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>
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Visibility

Use the .visible or .invisible classes to control the visibility of elements. Note: These classes do not change the CSS display value. They only add visibility:visible or visibility:hidden:

Example

I am visibile

Example

<div class="visible">I am visible</div>
<div class="invisible">I am invisible</div>
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Position

Use the .fixed-top class to make any element fixed/stay at the top of the page:

Example

<nav class="navbar navbar-expand-sm bg-dark navbar-dark fixed-top">
  ...
</nav>
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Use the .fixed-bottom class to make any element fixed/stay at the bottom of the page:

Example

<nav class="navbar navbar-expand-sm bg-dark navbar-dark fixed-bottom">
  ...
</nav>
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Use the .sticky-top class to make any element fixed/stay at the top of the page when you scroll past it. Note: This class does not work in IE11 and earlier (will treat it as position:relative).

Example

<nav class="navbar navbar-expand-sm bg-dark navbar-dark sticky-top">
  ...
</nav>
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Close icon

Use the .close class to style a close icon. This is often used for alerts and modals. Note that we use the &times; symbol to create the actual icon (a better lookiong "x"). Also note that it floats right by default:

Example

Example

<button type="button" class="close">&times;</button>
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Colors

As described in the Colors chapter, here is a list of all text and background color classes:

The classes for text colors are: .text-muted, .text-primary, .text-success, .text-info, .text-warning, .text-danger, .text-secondary, .text-white, .text-dark, .text-body (default body color/often black) and .text-light:

Example

This text is muted.

This text is important.

This text indicates success.

This text represents some information.

This text represents a warning.

This text represents danger.

Secondary text.

Dark grey text.

Body text.

Light grey text.

Try it Yourself »

Contextual text classes can also be used on links, which will add a darker hover color:

You can also add 50% opacity for black or white text with the .text-black-50 or .text-white-50 classes:

Example

Black text with 50% opacity on white background

White text with 50% opacity on black background

Try it Yourself »

Background Colors

The classes for background colors are: .bg-primary, .bg-success, .bg-info, .bg-warning, .bg-danger, .bg-secondary, .bg-dark and .bg-light.

Note that background colors do not set the text color, so in some cases you'll want to use them together with a .text-* class.

Example

This text is important.

This text indicates success.

This text represents some information.

This text represents a warning.

This text represents danger.

Secondary background color.

Dark grey background color.

Light grey background color.

Try it Yourself »

Typography/Text Classes

As described in the Typography chapter, here is a list of all typography/text classes:

Class Description Example
.display-* Display headings are used to stand out more than normal headings (larger font-size and lighter font-weight), and there are four classes to choose from: .display-1, .display-2, .display-3, .display-4 Try it
.font-weight-bold Bold text Try it
.font-weight-normal Normal text Try it
.font-weight-light Light weight text Try it
.font-italic Italic text Try it
.lead Makes a paragraph stand out Try it
.small Indicates smaller text (set to 85% of the size of the parent) Try it
.text-left Indicates left-aligned text Try it
.text-center Indicates center-aligned text Try it
.text-right Indicates right-aligned text Try it
.text-justify Indicates justified text Try it
.text-monospace Monospaced text Try it
.text-nowrap Indicates no wrap text Try it
.text-lowercase Indicates lowercased text Try it
.text-uppercase Indicates uppercased text Try it
.text-capitalize Indicates capitalized text Try it
.initialism Displays the text inside an <abbr> element in a slightly smaller font size Try it
.list-unstyled Removes the default list-style and left margin on list items (works on both <ul> and <ol>). This class only applies to immediate children list items (to remove the default list-style from any nested lists, apply this class to any nested lists as well) Try it
.list-inline Places all list items on a single line (used together with .list-inline-item on each <li> elements) Try it
.pre-scrollable Makes a <pre> element scrollable Try it

Block Elements

To make an element into a block element, add the .d-block class. Use any of the d-*-block classes to control WHEN the element should be a block element on a specific screen width:

Example

d-block d-sm-block d-md-block d-lg-block d-xl-block

Example

<span class="d-block bg-success">d-block</span>
<span class="d-sm-block bg-success">d-sm-block</span>
<span class="d-md-block bg-success">d-md-block</span>
<span class="d-lg-block bg-success">d-lg-block</span>
<span class="d-xl-block bg-success">d-xl-block</span>
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Flex

Use .flex-* classes to control the layout with flexbox.

Read more about Bootstrap 4 Flex, in our next chapter.

Example

Horizontal:

Flex item 1
Flex item 2
Flex item 3
Flex item 1
Flex item 2
Flex item 3

Vertical:

Flex item 1
Flex item 2
Flex item 3
Flex item 1
Flex item 2
Flex item 3