DocsGrid System
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.
How it works
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.
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 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 | ||||
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.
All 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.