Bootstrap includes a responsive, mobile first fluid grid system that appropriately scales up to 12 columns as the device or viewport size increases. It includes predefined classes for easy layout options, as well as powerful mixins for generating more semantic layouts.
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) or .container-fluid
(full-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 .rows.
.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.
Look to the examples for applying these principles to your code.
See how aspects of the Bootstrap grid system work across multiple devices with a handy dandy table.
| 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 | ||
| Container width | None (auto) | 750px | 970px | 1170px |
| Class prefix | .col-xs- |
.col-sm- |
.col-md- |
.col-lg- |
| # of columns | 12 | |||
| Column width | Auto | ~62px | ~81px | ~97px |
| Gutter width | 30px (15px on each side of a column) | |||
| Nestable | Yes | |||
| Offsets | Yes | |||
| Column ordering | Yes | |||
<div class="row show-grid">
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
<div class="col-md-1">.col-md-1</div>
</div>
<div class="row show-grid">
<div class="col-md-8">.col-md-8</div>
<div class="col-md-4">.col-md-4</div>
</div>
<div class="row show-grid">
<div class="col-md-4">.col-md-4</div>
<div class="col-md-4">.col-md-4</div>
<div class="col-md-4">.col-md-4</div>
</div>
<div class="row show-grid">
<div class="col-md-6">.col-md-6</div>
<div class="col-md-6">.col-md-6</div>
</div>
Turn any fixed-width grid layout into a full-width layout by changing your outermost
.container to .container-fluid.
<div class="container-fluid">
<div class="row">
...
</div>
</div>
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.
<div class="row show-grid">
<div class="col-xs-12 col-sm-6 col-md-8">.col-xs-12 .col-sm-6 .col-md-8</div>
<div class="col-xs-6 col-md-4">.col-xs-6 .col-md-4</div>
</div>
<div class="row show-grid">
<div class="col-xs-6 col-sm-4">.col-xs-6 .col-sm-4</div>
<div class="col-xs-6 col-sm-4">.col-xs-6 .col-sm-4</div>
<div class="clearfix visible-xs-block"></div>
<div class="col-xs-6 col-sm-4">.col-xs-6 .col-sm-4</div>
</div>
Build on the previous example by creating even more dynamic and powerful layouts with tablet .col-sm-*
classes.
<div class="row show-grid">
<div class="col-xs-6 col-sm-4">.col-xs-6 .col-sm-4</div>
<div class="col-xs-6 col-sm-4">.col-xs-6 .col-sm-4</div>
<div class="clearfix visible-xs-block"></div>
<div class="col-xs-6 col-sm-4">.col-xs-6 .col-sm-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 show-grid">
<div class="col-xs-9">.col-xs-9</div>
<div class="col-xs-4">.col-xs-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-xs-6">.col-xs-6<br>Subsequent columns continue along the new line.</div>
</div>
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.
<div class="row show-grid">
<div class="col-xs-6 col-sm-3"> .col-xs-6 .col-sm-3 <br> Resize your viewport or check it out on your
phone for an example.
</div>
<div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
<div class="clearfix visible-xs-block"></div>
<div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
<div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
</div>
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.
<div class="row show-grid">
<div class="col-md-4">.col-md-4</div>
<div class="col-md-4 col-md-offset-4">.col-md-4 .col-md-offset-4</div>
</div>
<div class="row show-grid">
<div class="col-md-3 col-md-offset-3">.col-md-3 .col-md-offset-3</div>
<div class="col-md-3 col-md-offset-3">.col-md-3 .col-md-offset-3</div>
</div>
<div class="row show-grid">
<div class="col-md-6 col-md-offset-3">.col-md-6 .col-md-offset-3</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 show-grid">
<div class="col-sm-9"> Level 1: .col-sm-9
<div class="row show-grid">
<div class="col-xs-8 col-sm-6"> Level 2: .col-xs-8 .col-sm-6</div>
<div class="col-xs-4 col-sm-6"> Level 2: .col-xs-4 .col-sm-6</div>
</div>
</div>
</div>