--- layout: docs title: Containers description: Containers are a fundamental building block of Bootstrap that contain, pad, and align your content within a given device or viewport. group: layout toc: true --- ## How they work 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 The table below illustrates how each container's `max-width` compares to the original `.container` and `.container-fluid` across each breakpoint. See them in action and compare them in our [Grid example]({{< docsref "/examples/grid#containers" >}}). {{< bs-table "table" >}} | | Extra small
<576px
| Small
≥576px
| Medium
≥768px
| Large
≥992px
| X-Large
≥1200px
| XX-Large
≥1400px
| | --- | --- | --- | --- | --- | --- | --- | | `.container` | 100% | 540px | 720px | 960px | 1140px | 1320px | | `.container-sm` | 100% | 540px | 720px | 960px | 1140px | 1320px | | `.container-md` | 100% | 100% | 720px | 960px | 1140px | 1320px | | `.container-lg` | 100% | 100% | 100% | 960px | 1140px | 1320px | | `.container-xl` | 100% | 100% | 100% | 100% | 1140px | 1320px | | `.container-xxl` | 100% | 100% | 100% | 100% | 100% | 1320px | | `.container-fluid` | 100% | 100% | 100% | 100% | 100% | 100% | {{< /bs-table >}} ## Default container Our default `.container` class is a responsive, fixed-width container, meaning its `max-width` changes at each breakpoint. ```html
``` ## Responsive containers Responsive containers allow you to specify a class that is 100% wide until the specified breakpoint is reached, after which we apply `max-width`s for each of the higher breakpoints. For example, `.container-sm` is 100% wide to start until the `sm` breakpoint is reached, where it will scale up with `md`, `lg`, `xl`, and `xxl`. ```html
100% wide until small breakpoint
100% wide until medium breakpoint
100% wide until large breakpoint
100% wide until extra large breakpoint
100% wide until extra extra large breakpoint
``` ## Fluid containers Use `.container-fluid` for a full width container, spanning the entire width of the viewport. ```html
...
``` ## 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: {{< scss-docs name="container-max-widths" file="scss/_variables.scss" >}} In addition to customizing the Sass, you can also create your own containers with our Sass mixin. ```scss // 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 to [the Sass section of the Grid documentation]({{< docsref "/layout/grid#sass" >}}).