---
layout: docs
title: Breakpoints
description: Breakpoints are customizable widths that determine how your responsive layout behaves across device or viewport sizes in Bootstrap.
group: layout
aliases: "/docs/5.1/layout/"
toc: true
---

## Core concepts

- **Breakpoints are the building blocks of responsive design.** Use them to control when your layout can be adapted at a particular viewport or device size.

- **Use media queries to architect your CSS by breakpoint.** Media queries are a feature of CSS that allow you to conditionally apply styles based on a set of browser and operating system parameters. We most commonly use `min-width` in our media queries.

- **Mobile first, responsive design is the goal.** Bootstrap's CSS aims to apply the bare minimum of styles to make a layout work at the smallest breakpoint, and then layers on styles to adjust that design for larger devices. This optimizes your CSS, improves rendering time, and provides a great experience for your visitors.

## Available breakpoints

Bootstrap includes six default breakpoints, sometimes referred to as _grid tiers_, for building responsively. These breakpoints can be customized if you're using our source Sass files.

<table class="table">
  <thead>
    <tr>
      <th>Breakpoint</th>
      <th>Class infix</th>
      <th>Dimensions</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Extra small</td>
      <td><em>None</em></td>
      <td>&lt;576px</td>
    </tr>
    <tr>
      <td>Small</td>
      <td><code>sm</code></td>
      <td>&ge;576px</td>
    </tr>
    <tr>
      <td>Medium</td>
      <td><code>md</code></td>
      <td>&ge;768px</td>
    </tr>
    <tr>
      <td>Large</td>
      <td><code>lg</code></td>
      <td>&ge;992px</td>
    </tr>
    <tr>
      <td>Extra large</td>
      <td><code>xl</code></td>
      <td>&ge;1200px</td>
    </tr>
    <tr>
      <td>Extra extra large</td>
      <td><code>xxl</code></td>
      <td>&ge;1400px</td>
    </tr>
  </tbody>
</table>

Each breakpoint was chosen to comfortably hold containers whose widths are multiples of 12. Breakpoints are also representative of a subset of common device sizes and viewport dimensions—they don't specifically target every use case or device. Instead, the ranges provide a strong and consistent foundation to build on for nearly any device.

These breakpoints are customizable via Sass—you'll find them in a Sass map in our `_variables.scss` stylesheet.

{{< scss-docs name="grid-breakpoints" file="scss/_variables.scss" >}}

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" >}}).

## Media queries

Since Bootstrap is developed to be mobile first, we use a handful of [media queries](https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queries/Using_media_queries) to create sensible breakpoints for our layouts and interfaces. These breakpoints are mostly based on minimum viewport widths and allow us to scale up elements as the viewport changes.

### Min-width

Bootstrap primarily uses the following media query ranges—or breakpoints—in our source Sass files for our layout, grid system, and components.

```scss
// Source mixins

// No media query necessary for xs breakpoint as it's effectively `@media (min-width: 0) { ... }`
@include media-breakpoint-up(sm) { ... }
@include media-breakpoint-up(md) { ... }
@include media-breakpoint-up(lg) { ... }
@include media-breakpoint-up(xl) { ... }
@include media-breakpoint-up(xxl) { ... }

// Usage

// Example: Hide starting at `min-width: 0`, and then show at the `sm` breakpoint
.custom-class {
  display: none;
}
@include media-breakpoint-up(sm) {
  .custom-class {
    display: block;
  }
}
```

These Sass mixins translate in our compiled CSS using the values declared in our Sass variables. For example:

```scss
// X-Small devices (portrait phones, less than 576px)
// No media query for `xs` since this is the default in Bootstrap

// Small devices (landscape phones, 576px and up)
@media (min-width: 576px) { ... }

// Medium devices (tablets, 768px and up)
@media (min-width: 768px) { ... }

// Large devices (desktops, 992px and up)
@media (min-width: 992px) { ... }

// X-Large devices (large desktops, 1200px and up)
@media (min-width: 1200px) { ... }

// XX-Large devices (larger desktops, 1400px and up)
@media (min-width: 1400px) { ... }
```

### Max-width

We occasionally use media queries that go in the other direction (the given screen size *or smaller*):

```scss
// No media query necessary for xs breakpoint as it's effectively `@media (max-width: 0) { ... }`
@include media-breakpoint-down(sm) { ... }
@include media-breakpoint-down(md) { ... }
@include media-breakpoint-down(lg) { ... }
@include media-breakpoint-down(xl) { ... }
@include media-breakpoint-down(xxl) { ... }

// Example: Style from medium breakpoint and down
@include media-breakpoint-down(md) {
  .custom-class {
    display: block;
  }
}
```

These mixins take those declared breakpoints, subtract `.02px` from them, and use them as our `max-width` values. For example:

```scss
// `xs` returns only a ruleset and no media query
// ... { ... }

// `sm` applies to x-small devices (portrait phones, less than 576px)
@media (max-width: 575.98px) { ... }

// `md` applies to small devices (landscape phones, less than 768px)
@media (max-width: 767.98px) { ... }

// `lg` applies to medium devices (tablets, less than 992px)
@media (max-width: 991.98px) { ... }

// `xl` applies to large devices (desktops, less than 1200px)
@media (max-width: 1199.98px) { ... }

// `xxl` applies to x-large devices (large desktops, less than 1400px)
@media (max-width: 1399.98px) { ... }
```

{{< callout warning >}}
{{< partial "callout-info-mediaqueries-breakpoints.md" >}}
{{< /callout >}}

### Single breakpoint

There are also media queries and mixins for targeting a single segment of screen sizes using the minimum and maximum breakpoint widths.

```scss
@include media-breakpoint-only(xs) { ... }
@include media-breakpoint-only(sm) { ... }
@include media-breakpoint-only(md) { ... }
@include media-breakpoint-only(lg) { ... }
@include media-breakpoint-only(xl) { ... }
@include media-breakpoint-only(xxl) { ... }
```

For example the `@include media-breakpoint-only(md) { ... }` will result in :

```scss
@media (min-width: 768px) and (max-width: 991.98px) { ... }
```

### Between breakpoints

Similarly, media queries may span multiple breakpoint widths:

```scss
@include media-breakpoint-between(md, xl) { ... }
```

Which results in:

```scss
// Example
// Apply styles starting from medium devices and up to extra large devices
@media (min-width: 768px) and (max-width: 1199.98px) { ... }
```
