--- 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.
Breakpoint Class infix Dimensions
Extra small None <576px
Small sm ≥576px
Medium md ≥768px
Large lg ≥992px
Extra large xl ≥1200px
Extra extra large xxl ≥1400px
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) { ... } ```