@use

Dart Sass: since 1.23.0
LibSass: ✗
Ruby Sass: ✗

Only Dart Sass currently supports @use. Users of other implementations must use the @import rule instead.

The @use rule loads mixins, functions, and variables from other Sass stylesheets, and combines CSS from multiple stylesheets together. Stylesheets loaded by @use are called "modules". Sass also provides built-in modules full of useful functions.

The simplest @use rule is written @use "<url>", which loads the module at the given URL. Any styles loaded this way will be included exactly once in the compiled CSS output, no matter how many times those styles are loaded.

⚠️ Heads up!

A stylesheet’s @use rules must come before any rules other than @forward, including style rules. However, you can declare variables before @use rules to use when configuring modules.

SCSS
Sass
CSS
SCSS Syntax// foundation/_code.scss
code {
  padding: .25em;
  line-height: 0;
}
// foundation/_lists.scss
ul, ol {
  text-align: left;

  & & {
    padding: {
      bottom: 0;
      left: 0;
    }
  }
}
// style.scss
@use 'foundation/code';
@use 'foundation/lists';
Sass Syntax// foundation/_code.sass
code
  padding: .25em
  line-height: 0

// foundation/_lists.sass
ul, ol
  text-align: left

  & &
    padding:
      bottom: 0
      left: 0



// style.sass
@use 'foundation/code'
@use 'foundation/lists'
CSS Outputcode {
  padding: .25em;
  line-height: 0;
}

ul, ol {
  text-align: left;
}
ul ul, ol ol {
  padding-bottom: 0;
  padding-left: 0;
}

Loading Members permalinkLoading Members

You can access variables, functions, and mixins from another module by writing <namespace>.<variable>, <namespace>.<function>(), or @include <namespace>.<mixin>(). By default, the namespace is just the last component of the module’s URL.

Members (variables, functions, and mixins) loaded with @use are only visible in the stylesheet that loads them. Other stylesheets will need to write their own @use rules if they also want to access them. This helps make it easy to figure out exactly where each member is coming from. If you want to load members from many files at once, you can use the @forward rule to forward them all from one shared file.

💡 Fun fact:

Because @use adds namespaces to member names, it’s safe to choose very simple names like $radius or $width when writing a stylesheet. This is different from the old @import rule, which encouraged that users write long names like $mat-corner-radius to avoid conflicts with other libraries, and it helps keep your stylesheets clear and easy to read!

SCSS
Sass
CSS
SCSS Syntax// src/_corners.scss
$radius: 3px;

@mixin rounded {
  border-radius: $radius;
}
// style.scss
@use "src/corners";

.button {
  @include corners.rounded;
  padding: 5px + corners.$radius;
}
Sass Syntax// src/_corners.sass
$radius: 3px

@mixin rounded
  border-radius: $radius

// style.sass
@use "src/corners"

.button
  @include corners.rounded
  padding: 5px + corners.$radius

CSS Output.button {
  border-radius: 3px;
  padding: 8px;
}

Choosing a Namespace permalinkChoosing a Namespace

By default, a module’s namespace is just the last component of its URL without a file extension. However, sometimes you might want to choose a different namespace—you might want to use a shorter name for a module you refer to a lot, or you might be loading multiple modules with the same filename. You can do this by writing @use "<url>" as <namespace>.

SCSS
Sass
CSS
SCSS Syntax// src/_corners.scss
$radius: 3px;

@mixin rounded {
  border-radius: $radius;
}
// style.scss
@use "src/corners" as c;

.button {
  @include c.rounded;
  padding: 5px + c.$radius;
}
Sass Syntax// src/_corners.sass
$radius: 3px

@mixin rounded
  border-radius: $radius

// style.sass
@use "src/corners" as c

.button
  @include c.rounded
  padding: 5px + c.$radius

CSS Output.button {
  border-radius: 3px;
  padding: 8px;
}

You can even load a module without a namespace by writing @use "<url>" as *. We recommend you only do this for stylesheets written by you, though; otherwise, they may introduce new members that cause name conflicts!

SCSS
Sass
CSS
SCSS Syntax// src/_corners.scss
$radius: 3px;

@mixin rounded {
  border-radius: $radius;
}
// style.scss
@use "src/corners" as *;

.button {
  @include rounded;
  padding: 5px + $radius;
}
Sass Syntax// src/_corners.sass
$radius: 3px

@mixin rounded
  border-radius: $radius

// style.sass
@use "src/corners" as *

.button
  @include rounded
  padding: 5px + $radius

CSS Output.button {
  border-radius: 3px;
  padding: 8px;
}

Private Members permalinkPrivate Members

As a stylesheet author, you may not want all the members you define to be available outside your stylesheet. Sass makes it easy to define a private member by starting its name with either - or _. These members will work just like normal within the stylesheet that defines them, but they won’t be part of a module’s public API. That means stylesheets that load your module can’t see them!

💡 Fun fact:

If you want to make a member private to an entire package rather than just a single module, just don’t forward its module from any of your package’s entrypoints (the stylesheets you tell your users to load to use your package). You can even hide that member while forwarding the rest of its module!

SCSS
Sass
SCSS Syntax// src/_corners.scss
$-radius: 3px;

@mixin rounded {
  border-radius: $-radius;
}
// style.scss
@use "src/corners";

.button {
  @include corners.rounded;

  // This is an error! $-radius isn't visible outside of `_corners.scss`.
  padding: 5px + corners.$-radius;
}
Sass Syntax// src/_corners.sass
$-radius: 3px

@mixin rounded
  border-radius: $-radius

// style.sass
@use "src/corners"

.button
  @include corners.rounded

  // This is an error! $-radius isn't visible outside of `_corners.scss`.
  padding: 5px + corners.$-radius

Configuration permalinkConfiguration

A stylesheet can define variables with the !default flag to make them configurable. To load a module with configuration, write @use <url> with (<variable>: <value>, <variable>: <value>). The configured values will override the variables’ default values.

SCSS
Sass
CSS
SCSS Syntax// _library.scss
$black: #000 !default;
$border-radius: 0.25rem !default;
$box-shadow: 0 0.5rem 1rem rgba($black, 0.15) !default;

code {
  border-radius: $border-radius;
  box-shadow: $box-shadow;
}
// style.scss
@use 'library' with (
  $black: #222,
  $border-radius: 0.1rem
);
Sass Syntax// _library.sass
$black: #000 !default
$border-radius: 0.25rem !default
$box-shadow: 0 0.5rem 1rem rgba($black, 0.15) !default

code
  border-radius: $border-radius
  box-shadow: $box-shadow

// style.sass
@use 'library' with ($black: #222, $border-radius: 0.1rem)



CSS Outputcode {
  border-radius: 0.1rem;
  box-shadow: 0 0.5rem 1rem rgba(34, 34, 34, 0.15);
}

With Mixins permalinkWith Mixins

Configuring modules with @use ... with can be very handy, especially when using libraries that were originally written to work with the @import rule. But it’s not particularly flexible, and we don’t recommend it for more advanced use-cases. If you find yourself wanting to configure many variables at once, pass maps as configuration, or update the configuration after the module is loaded, consider writing a mixin to set your variables instead and another mixin to inject your styles.

SCSS
Sass
CSS
SCSS Syntax// _library.scss
$-black: #000;
$-border-radius: 0.25rem;
$-box-shadow: null;

/// If the user has configured `$-box-shadow`, returns their configured value.
/// Otherwise returns a value derived from `$-black`.
@function -box-shadow() {
  @return $-box-shadow or (0 0.5rem 1rem rgba($-black, 0.15));
}

@mixin configure($black: null, $border-radius: null, $box-shadow: null) {
  @if $black {
    $-black: $black !global;
  }
  @if $border-radius {
    $-border-radius: $border-radius !global;
  }
  @if $box-shadow {
    $-box-shadow: $box-shadow !global;
  }
}

@mixin styles {
  code {
    border-radius: $-border-radius;
    box-shadow: -box-shadow();
  }
}
// style.scss
@use 'library';

@include library.configure(
  $black: #222,
  $border-radius: 0.1rem
);

@include library.styles;
Sass Syntax// _library.sass
$-black: #000
$-border-radius: 0.25rem
$-box-shadow: null

/// If the user has configured `$-box-shadow`, returns their configured value.
/// Otherwise returns a value derived from `$-black`.
@function -box-shadow()
  @return $-box-shadow or (0 0.5rem 1rem rgba($-black, 0.15))


@mixin configure($black: null, $border-radius: null, $box-shadow: null)
  @if $black
    $-black: $black !global
  @if $border-radius
    $-border-radius: $border-radius !global
  @if $box-shadow
    $-box-shadow: $box-shadow !global


@mixin styles
  code
    border-radius: $-border-radius
    box-shadow: -box-shadow()





// style.sass
@use 'library'
@include library.configure($black: #222, $border-radius: 0.1rem)
@include library.styles





CSS Outputcode {
  border-radius: 0.1rem;
  box-shadow: 0 0.5rem 1rem rgba(34, 34, 34, 0.15);
}

Reassigning Variables permalinkReassigning Variables

After loading a module, you can reassign its variables.

SCSS
Sass
SCSS Syntax// _library.scss
$color: red;
// _override.scss
@use 'library';
library.$color: blue;
// style.scss
@use 'library';
@use 'override';
@debug library.$color;  //=> blue
Sass Syntax// _library.sass
$color: red
// _override.sass
@use 'library'
library.$color: blue
// style.sass
@use 'library'
@use 'override'
@debug library.$color  //=> blue

This even works if you import a module without a namespace using as *. Assigning to a variable name defined in that module will overwrite its value in that module.

⚠️ Heads up!

Built-in module variables (such as math.$pi) cannot be reassigned.

Finding the Module permalinkFinding the Module

It wouldn’t be any fun to write out absolute URLs for every stylesheet you load, so Sass’s algorithm for finding a module makes it a little easier. For starters, you don’t have to explicitly write out the extension of the file you want to load; @use "variables" will automatically load variables.scss, variables.sass, or variables.css.

⚠️ Heads up!

To ensure that stylesheets work on every operating system, Sass loads files by URL, not by file path. This means you need to use forward slashes, not backslashes, even on Windows.

Load Paths permalinkLoad Paths

All Sass implementations allow users to provide load paths: paths on the filesystem that Sass will look in when locating modules. For example, if you pass node_modules/susy/sass as a load path, you can use @use "susy" to load node_modules/susy/sass/susy.scss.

Modules will always be loaded relative to the current file first, though. Load paths will only be used if no relative file exists that matches the module’s URL. This ensures that you can’t accidentally mess up your relative imports when you add a new library.

💡 Fun fact:

Unlike some other languages, Sass doesn’t require that you use ./ for relative imports. Relative imports are always available.

Partials permalinkPartials

As a convention, Sass files that are only meant to be loaded as modules, not compiled on their own, begin with _ (as in _code.scss). These are called partials, and they tell Sass tools not to try to compile those files on their own. You can leave off the _ when importing a partial.

Index Files permalinkIndex Files

If you write an _index.scss or _index.sass in a folder, the index file will be loaded automatically when you load the URL for the folder itself.

SCSS
Sass
CSS
SCSS Syntax// foundation/_code.scss
code {
  padding: .25em;
  line-height: 0;
}
// foundation/_lists.scss
ul, ol {
  text-align: left;

  & & {
    padding: {
      bottom: 0;
      left: 0;
    }
  }
}
// foundation/_index.scss
@use 'code';
@use 'lists';
// style.scss
@use 'foundation';
Sass Syntax// foundation/_code.sass
code
  padding: .25em
  line-height: 0

// foundation/_lists.sass
ul, ol
  text-align: left

  & &
    padding:
      bottom: 0
      left: 0



// foundation/_index.sass
@use 'code'
@use 'lists'
// style.sass
@use 'foundation'
CSS Outputcode {
  padding: .25em;
  line-height: 0;
}

ul, ol {
  text-align: left;
}
ul ul, ol ol {
  padding-bottom: 0;
  padding-left: 0;
}

Loading CSS permalinkLoading CSS

In addition to loading .sass and .scss files, Sass can load plain old .css files.

SCSS
Sass
CSS
SCSS Syntax// code.css
code {
  padding: .25em;
  line-height: 0;
}
// style.scss
@use 'code';
Sass Syntax// code.css
code {
  padding: .25em;
  line-height: 0;
}
// style.sass
@use 'code'
CSS Outputcode {
  padding: .25em;
  line-height: 0;
}

CSS files loaded as modules don’t allow any special Sass features and so can’t expose any Sass variables, functions, or mixins. In order to make sure authors don’t accidentally write Sass in their CSS, all Sass features that aren’t also valid CSS will produce errors. Otherwise, the CSS will be rendered as-is. It can even be extended!

Differences From @import permalinkDifferences From `@import`

The @use rule is intended to replace the old @import rule, but it’s intentionally designed to work differently. Here are some major differences between the two:

@use only makes variables, functions, and mixins available within the scope of the current file. It never adds them to the global scope. This makes it easy to figure out where each name your Sass file references comes from, and means you can use shorter names without any risk of collision.
@use only ever loads each file once. This ensures you don’t end up accidentally duplicating your dependencies’ CSS many times over.
@use must appear at the beginning your file, and cannot be nested in style rules.
Each @use rule can only have one URL.
@use requires quotes around its URL, even when using the indented syntax.

@use

⚠️ Heads up!

SCSS Syntax

Sass Syntax

CSS Output

Loading Members permalinkLoading Members

💡 Fun fact:

SCSS Syntax

Sass Syntax

CSS Output

Choosing a Namespace permalinkChoosing a Namespace

SCSS Syntax

Sass Syntax

CSS Output

SCSS Syntax

Sass Syntax

CSS Output

Private Members permalinkPrivate Members

💡 Fun fact:

SCSS Syntax

Sass Syntax

Configuration permalinkConfiguration

SCSS Syntax

Sass Syntax

CSS Output

With Mixins permalinkWith Mixins

SCSS Syntax

Sass Syntax

CSS Output

Reassigning Variables permalinkReassigning Variables

SCSS Syntax

Sass Syntax

⚠️ Heads up!

Finding the Module permalinkFinding the Module

⚠️ Heads up!

Load Paths permalinkLoad Paths

💡 Fun fact:

Partials permalinkPartials

Index Files permalinkIndex Files

SCSS Syntax

Sass Syntax

CSS Output

Loading CSS permalinkLoading CSS

SCSS Syntax

Sass Syntax

CSS Output

Differences From @import permalinkDifferences From @import

Differences From @import permalinkDifferences From `@import`