Containers are a fundamental building block of Bootstrap that contain, pad, and align your content within a given device or viewport.

How they work

Containers are the most basic layout element in Bootstrap and arerequired when using our default grid system. Containers are used to contain, pad, and (sometimes) center the content within them. While containerscan be nested, most layouts do not require a nested container.

Bootstrap comes with three different containers:

• .container, which sets amax-width at each responsive breakpoint
• .container-fluid, which iswidth: 100% at all breakpoints
• .container-{breakpoint}, which iswidth: 100% until the specified breakpoint

The table below illustrates how each container’smax-width compares to the original.container and.container-fluid across each breakpoint.

See them in action and compare them in ourGrid example.

Default container

Our default.container class is a responsive, fixed-width container, meaning itsmax-width changes at each breakpoint.

<divclass="container"><!-- Content here --></div>

Responsive containers

Responsive containers allow you to specify a class that is 100% wide until the specified breakpoint is reached, after which we applymax-widths for each of the higher breakpoints. For example,.container-sm is 100% wide to start until thesm breakpoint is reached, where it will scale up withmd,lg,xl, andxxl.

<divclass="container-sm">100% wide until small breakpoint</div><divclass="container-md">100% wide until medium breakpoint</div><divclass="container-lg">100% wide until large breakpoint</div><divclass="container-xl">100% wide until extra large breakpoint</div><divclass="container-xxl">100% wide until extra extra large breakpoint</div>

Fluid containers

Use.container-fluid for a full width container, spanning the entire width of the viewport.

<divclass="container-fluid">  ...</div>

Sass

As shown above, Bootstrap generates a series of predefined container classes to help you build the layouts you desire. You may customize these predefined container classes by modifying the Sass map (found in_variables.scss) that powers them:

$container-max-widths:(sm:540px,md:720px,lg:960px,xl:1140px,xxl:1320px);

In addition to customizing the Sass, you can also create your own containers with our Sass mixin.

// Source mixin@mixin make-container($padding-x:$container-padding-x){width:100%;padding-right:$padding-x;padding-left:$padding-x;margin-right:auto;margin-left:auto;}// Usage.custom-container{@include make-container();}

For more information and examples on how to modify our Sass maps and variables, please refer tothe Sass section of the Grid documentation.