Bootstrap includes a responsive, mobile first fluid grid system that appropriately scales up to 12 columns as the device or viewport size increases.
Grid systems are used for creating page layouts through a series of rows and columns that house your content. Here's how the Bootstrap grid system works:
.container
(fixed-width) for proper alignment and padding..row
and .col-xs-4
are available for quickly making grid layouts. Less mixins can also be used for more semantic layouts.padding
. That padding is offset in rows for the first and last column via negative margin on .row
s..col-xs-4
..col-md-*
class to an element will not only affect its styling on medium devices but also on large devices if a .col-lg-*
class is not present.Bootstrap uses the following media queries to create the key breakpoints in the grid system.
Extra small devices Phones (<768px) | Small devices Tablets (≥768px) | Medium devices Desktops (≥992px) | Large devices Desktops (≥1200px) | |
---|---|---|---|---|
Grid behavior | Horizontal at all times | Collapsed to start, horizontal above breakpoints | ||
Max container width | None (auto) | 750px | 970px | 1170px |
Class prefix |
.col-xs-
|
.col-sm-
|
.col-md-
|
.col-lg-
|
# of columns | 12 | |||
Max column width | Auto | ~60px | ~78px | ~95px |
Gutter width | 30px (15px on each side of a column) | |||
Nestable | Yes | |||
Offsets | Yes | |||
Column ordering | Yes |
Grid classes apply to devices with screen widths greater than or equal to the breakpoint sizes, and override grid classes targeted at smaller devices. Therefore, applying any .col-md-
class to an element will not only affect its styling on medium devices but also on large devices if a .col-lg-
class is not present.
Using a single set of .col-md-*
grid classes, you can create a basic grid system that starts out stacked on mobile devices and tablet devices (the extra small to small range) before becoming horizontal on desktop (medium) devices. Place grid columns in any .row
.
Don't want your columns to simply stack in smaller devices? Use the extra small and medium device grid classes by adding .col-xs-*
.col-md-*
to your columns. See the example below for a better idea of how it all works.
Build on the previous example by creating even more dynamic and powerful layouts with tablet .col-sm-*
classes.
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.
With the four tiers of grids available you're bound to run into issues where, at certain breakpoints, your columns don't clear quite right as one is taller than the other. To fix that, use a combination of a .clearfix
and our responsive utility classes.
Move columns to the right using .col-md-offset-*
classes. These classes increase the left margin of a column by *
columns. For example, .col-md-offset-4
moves .col-md-4
over four columns.
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).
Easily change the order of our built-in grid columns with .col-md-push-*
and .col-md-pull-*
modifier classes.