Bootstrap Grid
Our Bootstrap grid is a powerful mobile-first flexbox grid which helps you 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.
Grid System
Bootstrap grid system uses a series of containers, rows, and columns to layout and aligns 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.
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
.
Grid Options
While Bootstrap uses
em
s or
rem
s for
defining most sizes,
px
s 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 |
Auto-layout columns
Utilize breakpoint-specific column classes for easy column sizing
without an explicit numbered class like
.col-sm-6
.
Equal-width
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.
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.
Setting one column width
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.
Variable width content
Use
col-{breakpoint}-auto
classes to size columns based on the natural width of their content.
Equal-width multi-row
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.
Responsive Classes
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.
Breakpoints
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
.
Stacked to horizontal
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
).
Mix and match
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.
Layout
For faster mobile-friendly and responsive development, Bootstrap includes dozens of utility classes for showing, hiding, aligning, and spacing content.
Container
Containers are the most basic layout element in Bootstrap and are required when using our default grid system. Containers are used to contain, pad, and (sometimes) center the content within them. While containers can be nested, most layouts do not require a nested container.
Bootstrap comes with three different containers:
-
.container
, which sets a max-width at each responsive breakpoint -
.container-fluid
, which is width: 100% at all breakpoints -
.container-{breakpoint}
, which is width: 100% until the specified breakpoint