Use our powerful mobile-first flexbox grid to build layouts of all shapes and sizes thanks to a twelve column system, five default responsive tiers, Sass variables and mixins, and dozens of predefined classes.
Bootstrap’s grid system uses a series of containers, rows, and columns to layout and align content. It’s built with flexbox and is fully responsive. Below is an example and an in-depth look at how the grid comes together.
New to or unfamiliar with flexbox? Read this CSS Tricks flexbox guide for background, terminology, guidelines, and code snippets.
<div class="container">
<div class="row">
<div class="col-sm">
One of three columns
</div>
<div class="col-sm">
One of three columns
</div>
<div class="col-sm">
One of three columns
</div>
</div>
</div>
The above example creates three equal-width columns on small, medium, large, and extra large devices using our predefined grid classes. Those columns are centered in the page with the parent .container.
Breaking it down, here’s how it works:
.container for a responsive pixel width or .container-fluid
for
width: 100% across all viewport and device sizes.padding (called a gutter) for controlling the space between them. This padding
is then counteracted on the rows with negative margins. This way, all the content in your columns is visually aligned down the left side.width will automatically layout as equal width columns. For example, four instances of .col-sm
will each automatically be 25% wide from the small breakpoint and up. See the auto-layout columns section for more examples..col-4.widths are set in percentages, so they’re always fluid and sized relative to their parent element.padding to create the gutters between individual columns, however, you can remove the margin
from rows and padding from columns with .no-gutters on the .row..col-sm-4
applies to small, medium, large, and extra large devices, but not the first xs breakpoint)..col-4) or Sass mixins for more semantic markup.Be aware of the limitations and bugs around flexbox, like the inability to use some HTML elements as flex containers.
While Bootstrap uses ems or rems for defining most sizes, pxs are used for grid
breakpoints and container widths. This is because the viewport width is in pixels and does not change with the font size.
See how aspects of the Bootstrap grid system work across multiple devices with a handy table.
|
Extra small
<576px |
Small
≥576px |
Medium
≥768px |
Large
≥992px |
Extra large
≥1200px |
|
|---|---|---|---|---|---|
| Max container width | None (auto) | 540px | 720px | 960px | 1140px |
| Class prefix | .col- |
.col-sm- |
.col-md- |
.col-lg- |
.col-xl- |
| # of columns | 12 | ||||
| Gutter width | 30px (15px on each side of a column) | ||||
| Nestable | Yes | ||||
| Column ordering | Yes | ||||
Utilize breakpoint-specific column classes for easy column sizing without an explicit numbered class like .col-sm-6.
For example, here are two grid layouts that apply to every device and viewport, from xs to xl. Add any number of unit-less
classes for each breakpoint you need and every column will be the same width.
<div class="container">
<div class="row">
<div class="col">
1 of 2
</div>
<div class="col">
2 of 2
</div>
</div>
<div class="row">
<div class="col">
1 of 3
</div>
<div class="col">
2 of 3
</div>
<div class="col">
3 of 3
</div>
</div>
</div>
Equal-width columns can be broken into multiple lines, but there was a Safari flexbox bug that prevented this from working without an
explicit
flex-basis or border. There are workarounds for older browser versions, but they shouldn’t be necessary if you’re
up-to-date.
<div class="container">
<div class="row">
<div class="col">Column</div>
<div class="col">Column</div>
<div class="w-100"></div>
<div class="col">Column</div>
<div class="col">Column</div>
</div>
</div>
Auto-layout for flexbox grid columns also means you can set the width of one column and have the sibling columns automatically resize around it. You may use predefined grid classes (as shown below), grid mixins, or inline widths. Note that the other columns will resize no matter the width of the center column.
<div class="container">
<div class="row">
<div class="col">
1 of 3
</div>
<div class="col-6">
2 of 3 (wider)
</div>
<div class="col">
3 of 3
</div>
</div>
<div class="row">
<div class="col">
1 of 3
</div>
<div class="col-5">
2 of 3 (wider)
</div>
<div class="col">
3 of 3
</div>
</div>
</div>
Use col-{breakpoint}-auto classes to size columns based on the natural width of their content.
<div class="container">
<div class="row justify-content-md-center">
<div class="col col-lg-2">
1 of 3
</div>
<div class="col-md-auto">
Variable width content
</div>
<div class="col col-lg-2">
3 of 3
</div>
</div>
<div class="row">
<div class="col">
1 of 3
</div>
<div class="col-md-auto">
Variable width content
</div>
<div class="col col-lg-2">
3 of 3
</div>
</div>
</div>
Create equal-width columns that span multiple rows by inserting a .w-100 where you want the columns to break to a new line. Make the breaks responsive by mixing
the
.w-100 with some responsive display utilities.
<div class="row">
<div class="col">col</div>
<div class="col">col</div>
<div class="w-100"></div>
<div class="col">col</div>
<div class="col">col</div>
</div>
Bootstrap’s grid includes five tiers of predefined classes for building complex responsive layouts. Customize the size of your columns on extra small, small, medium, large, or extra large devices however you see fit.
For grids that are the same from the smallest of devices to the largest, use the .col and .col-* classes. Specify a numbered
class when you need a particularly sized column; otherwise, feel free to stick to .col.
<div class="row">
<div class="col">col</div>
<div class="col">col</div>
<div class="col">col</div>
<div class="col">col</div>
</div>
<div class="row">
<div class="col-8">col-8</div>
<div class="col-4">col-4</div>
</div>
Using a single set of .col-sm-* classes, you can create a basic grid system that starts out stacked and becomes horizontal at the small breakpoint (sm).
<div class="row">
<div class="col-sm-8">col-sm-8</div>
<div class="col-sm-4">col-sm-4</div>
</div>
<div class="row">
<div class="col-sm">col-sm</div>
<div class="col-sm">col-sm</div>
<div class="col-sm">col-sm</div>
</div>
Don’t want your columns to simply stack in some grid tiers? Use a combination of different classes for each tier as needed. See the example below for a better idea of how it all works.
<!-- Stack the columns on mobile by making one full-width and the other half-width -->
<div class="row">
<div class="col-12 col-md-8">.col-12 .col-md-8</div>
<div class="col-6 col-md-4">.col-6 .col-md-4</div>
</div>
<!-- Columns start at 50% wide on mobile and bump up to 33.3% wide on desktop -->
<div class="row">
<div class="col-6 col-md-4">.col-6 .col-md-4</div>
<div class="col-6 col-md-4">.col-6 .col-md-4</div>
<div class="col-6 col-md-4">.col-6 .col-md-4</div>
</div>
<!-- Columns are always 50% wide, on mobile and desktop -->
<div class="row">
<div class="col-6">.col-6</div>
<div class="col-6">.col-6</div>
</div>
Use flexbox alignment utilities to vertically and horizontally align columns.
<div class="container">
<div class="row align-items-start">
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
</div>
<div class="row align-items-center">
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
</div>
<div class="row align-items-end">
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
</div>
</div>
<div class="container">
<div class="row">
<div class="col align-self-start">
One of three columns
</div>
<div class="col align-self-center">
One of three columns
</div>
<div class="col align-self-end">
One of three columns
</div>
</div>
</div>
<div class="container">
<div class="row justify-content-start">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
<div class="row justify-content-center">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
<div class="row justify-content-end">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
<div class="row justify-content-around">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
<div class="row justify-content-between">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
</div>
The gutters between columns in our predefined grid classes can be removed with .no-gutters. This removes the negative margins
from
.row and the horizontal padding from all immediate children columns.
Here’s the source code for creating these styles. Note that column overrides are scoped to only the first children columns and are targeted via attribute selector. While this generates a more specific selector, column padding can still be further customized with spacing utilities.
Need an edge-to-edge design? Drop the parent .container or .container-fluid.
.no-gutters {
margin-right: 0;
margin-left: 0;
> .col,
> [class*="col-"] {
padding-right: 0;
padding-left: 0;
}
}
In practice, here’s how it looks. Note you can continue to use this with all other predefined grid classes (including column widths, responsive tiers, reorders, and more).
<div class="row no-gutters">
<div class="col-12 col-sm-6 col-md-8">.col-12 .col-sm-6 .col-md-8</div>
<div class="col-6 col-md-4">.col-6 .col-md-4</div>
</div>
If more than 12 columns are placed within a single row, each group of extra columns will, as one unit, wrap onto a new line.
<div class="row">
<div class="col-9">.col-9</div>
<div class="col-4">.col-4
<br />Since 9 + 4 = 13 > 12, this 4-column-wide div gets wrapped onto a new line as one contiguous unit.
</div>
<div class="col-6">.col-6
<br />Subsequent columns continue along the new line.
</div>
</div>
Breaking columns to a new line in flexbox requires a small hack: add an element with width: 100% wherever you want to wrap your columns to a new line. Normally
this is accomplished with multiple
.rows, but not every implementation method can account for this.
<div class="row">
<div class="col-6 col-sm-3">.col-6 .col-sm-3</div>
<div class="col-6 col-sm-3">.col-6 .col-sm-3</div>
<!-- Force next columns to break to new line -->
<div class="w-100"></div>
<div class="col-6 col-sm-3">.col-6 .col-sm-3</div>
<div class="col-6 col-sm-3">.col-6 .col-sm-3</div>
</div>
You may also apply this break at specific breakpoints with our responsive display utilities.
<div class="row">
<div class="col-6 col-sm-4">.col-6 .col-sm-4</div>
<div class="col-6 col-sm-4">.col-6 .col-sm-4</div>
<!-- Force next columns to break to new line at md breakpoint and up -->
<div class="w-100 d-none d-md-block"></div>
<div class="col-6 col-sm-4">.col-6 .col-sm-4</div>
<div class="col-6 col-sm-4">.col-6 .col-sm-4</div>
</div>
Use .order- classes for controlling the visual order of your content. These classes are responsive, so you can set the order
by breakpoint (e.g., .order-1.order-md-2). Includes support for 1 through 12 across
all five grid tiers.
<div class="container">
<div class="row">
<div class="col">
First, but unordered
</div>
<div class="col order-12">
Second, but last
</div>
<div class="col order-1">
Third, but first
</div>
</div>
</div>
There are also responsive .order-first and .order-last classes that change the order
of an element by applying
order: -1 and order: 13 (order: $columns + 1), respectively. These classes can also
be intermixed with the numbered
.order-* classes as needed.
<div class="container">
<div class="row">
<div class="col order-last">
First, but last
</div>
<div class="col">
Second, but unordered
</div>
<div class="col order-first">
Third, but first
</div>
</div>
</div>
You can offset grid columns in two ways: our responsive .offset- grid classes and our margin utilities. Grid classes are
sized to match columns while margins are more useful for quick layouts where the width of the offset is variable.
Move columns to the right using .offset-md-* classes. These classes increase the left margin of a column by * columns. For
example,
.offset-md-4 moves .col-md-4 over four columns.
<div class="row">
<div class="col-md-4">.col-md-4</div>
<div class="col-md-4 offset-md-4">.col-md-4 .offset-md-4</div>
</div>
<div class="row">
<div class="col-md-3 offset-md-3">.col-md-3 .offset-md-3</div>
<div class="col-md-3 offset-md-3">.col-md-3 .offset-md-3</div>
</div>
<div class="row">
<div class="col-md-6 offset-md-3">.col-md-6 .offset-md-3</div>
</div>
In addition to column clearing at responsive breakpoints, you may need to reset offsets. See this in action in the grid example.
<div class="row">
<div class="col-sm-5 col-md-6">.col-sm-5 .col-md-6</div>
<div class="col-sm-5 offset-sm-2 col-md-6 offset-md-0">.col-sm-5 .offset-sm-2 .col-md-6 .offset-md-0</div>
</div>
<div class="row">
<div class="col-sm-6 col-md-5 col-lg-6">.col-sm-6 .col-md-5 .col-lg-6</div>
<div class="col-sm-6 col-md-5 offset-md-2 col-lg-6 offset-lg-0">.col-sm-6 .col-md-5 .offset-md-2 .col-lg-6 .offset-lg-0</div>
</div>
With the move to flexbox in v4, you can use margin utilities like .mr-auto to force sibling columns away from one another.
<div class="row">
<div class="col-md-4">.col-md-4</div>
<div class="col-md-4 ml-auto">.col-md-4 .ml-auto</div>
</div>
<div class="row">
<div class="col-md-3 ml-md-auto">.col-md-3 .ml-md-auto</div>
<div class="col-md-3 ml-md-auto">.col-md-3 .ml-md-auto</div>
</div>
<div class="row">
<div class="col-auto mr-auto">.col-auto .mr-auto</div>
<div class="col-auto">.col-auto</div>
</div>
To nest your content with the default grid, add a new .row and set of .col-sm-* columns within an existing .col-sm-*
column. Nested rows should include a set of columns that add up to 12 or fewer (it is not required that you use all 12 available columns).
<div class="row">
<div class="col-sm-9">
Level 1: .col-sm-9
<div class="row">
<div class="col-8 col-sm-6">
Level 2: .col-8 .col-sm-6
</div>
<div class="col-4 col-sm-6">
Level 2: .col-4 .col-sm-6
</div>
</div>
</div>
</div>
When using Bootstrap’s source Sass files, you have the option of using Sass variables and mixins to create custom, semantic, and responsive page layouts. Our predefined grid classes use these same variables and mixins to provide a whole suite of ready-to-use classes for fast responsive layouts.
Variables and maps determine the number of columns, the gutter width, and the media query point at which to begin floating columns. We use these to generate the predefined grid classes documented above, as well as for the custom mixins listed below.
$grid-columns: 12;
$grid-gutter-width: 30px;
$grid-breakpoints: (
// Extra small screen / phone
xs: 0,
// Small screen / phone
sm: 576px,
// Medium screen / tablet
md: 768px,
// Large screen / desktop
lg: 992px,
// Extra large screen / wide desktop
xl: 1200px
);
$container-max-widths: (
sm: 540px,
md: 720px,
lg: 960px,
xl: 1140px
);
Mixins are used in conjunction with the grid variables to generate semantic CSS for individual grid columns.
// Creates a wrapper for a series of columns
@include make-row();
// Make the element grid-ready (applying everything but the width)
@include make-col-ready();
@include make-col($size, $columns: $grid-columns);
// Get fancy by offsetting, or changing the sort order
@include make-col-offset($size, $columns: $grid-columns);
You can modify the variables to your own custom values, or just use the mixins with their default values. Here’s an example of using the default settings to create a two-column layout with a gap between.
.example-container {
width: 800px;
@include make-container();
}
.example-row {
@include make-row();
}
.example-content-main {
@include make-col-ready();
@include media-breakpoint-up(sm) {
@include make-col(6);
}
@include media-breakpoint-up(lg) {
@include make-col(8);
}
}
.example-content-secondary {
@include make-col-ready();
@include media-breakpoint-up(sm) {
@include make-col(6);
}
@include media-breakpoint-up(lg) {
@include make-col(4);
}
}
<div class="example-container">
<div class="example-row">
<div class="example-content-main">Main content</div>
<div class="example-content-secondary">Secondary content</div>
</div>
</div>
Using our built-in grid Sass variables and maps, it’s possible to completely customize the predefined grid classes. Change the number of tiers, the media query dimensions, and the container widths—then recompile.
The number of grid columns can be modified via Sass variables. $grid-columns is used to generate the widths (in percent) of each individual column while $grid-gutter-width
allows breakpoint-specific widths that are divided evenly across padding-left and padding-right
for the column gutters.
$grid-columns: 12 !default;
$grid-gutter-width: 30px !default;
Moving beyond the columns themselves, you may also customize the number of grid tiers. If you wanted just four grid tiers, you’d update the $grid-breakpoints and
$container-max-widths to something like this:
$grid-breakpoints: (
xs: 0,
sm: 480px,
md: 768px,
lg: 1024px
);
$container-max-widths: (
sm: 420px,
md: 720px,
lg: 960px
);
When making any changes to the Sass variables or maps, you’ll need to save your changes and recompile. Doing so will output a brand new set of predefined grid classes for column widths, offsets, and
ordering. Responsive visibility utilities will also be updated to use the custom breakpoints. Make sure to set grid values in px (not rem,
em, or %).