@media

The @media CSS at-rule can be used to apply part of a style sheet based on the result of one or more media queries. With it, you specify a media query and a block of CSS to apply to the document if and only if the media query matches the device on which the content is being used.

Syntax

The @media at-rule may be placed at the top level of your code or nested inside any other conditional group at-rule.

/* At the top level of your code */
@media screen and (min-width: 900px) {
  article {
    padding: 1rem 3rem;
  }
}

/* Nested within another conditional at-rule */
@supports (display: flex) {
  @media screen and (min-width: 900px) {
    article {
      display: flex;
    }
  }
}

For a discussion of media query syntax, please see Using media queries.

Description

Media types

Media types describe the general category of a device. Except when using the not or only logical operators, the media type is optional and the all type will be implied.

all

Suitable for all devices.

print

Intended for paged material and documents viewed on a screen in print preview mode. (Please see paged media for information about formatting issues that are specific to these formats.)

screen

Intended primarily for screens.

speech

Intended for speech synthesizers.

Media features

Media features describe specific characteristics of the user agent, output device, or environment. Media feature expressions test for their presence or value, and are entirely optional. Each media feature expression must be surrounded by parentheses.

Accessibility concerns

To best accommodate people who adjust a site's text size, use ems when you need a <length> for your media queries.

Both em and px are valid units, but em works better if the user changes the browser text size.

Also consider using Level 4 media queries to improve the user's experience. For example, prefers-reduced-motion to detect if the user has requested that the system minimize the amount of animation or motion it uses.

Security

Because media queries provide insights into the capabilities—and by extension, the features and design—of the device the user is working with, there is the potential that they could be abused to construct a "fingerprint" which identifies the device, or at least categorizes it to some degree of detail that may be undesirable to users.

Because of this potential, a browser may opt to fudge the returned values in some manner in order to prevent them from being used to precisely identify a computer. A browser might also offer additional measures in this area; for example, if Firefox's "Resist Fingerprinting" setting is enabled, many media queries report default values rather than values representing the actual device state.

Formal syntax

@media <media-query-list> {
  <group-rule-body>
}
where 
<media-query-list> = <media-query>#
where 
<media-query> = <media-condition> | [ not | only ]? <media-type> [ and <media-condition-without-or> ]?
where 
<media-condition> = <media-not> | <media-and> | <media-or> | <media-in-parens>
<media-type> = <ident>
<media-condition-without-or> = <media-not> | <media-and> | <media-in-parens>
where 
<media-not> = not <media-in-parens>
<media-and> = <media-in-parens> [ and <media-in-parens> ]+
<media-or> = <media-in-parens> [ or <media-in-parens> ]+
<media-in-parens> = ( <media-condition> ) | <media-feature> | <general-enclosed>
where 
<media-feature> = ( [ <mf-plain> | <mf-boolean> | <mf-range> ] )
<general-enclosed> = [ <function-token> <any-value> ) ] | ( <ident> <any-value> )
where 
<mf-plain> = <mf-name> : <mf-value>
<mf-boolean> = <mf-name>
<mf-range> = <mf-name> [ '<' | '>' ]? '='? <mf-value> | <mf-value> [ '<' | '>' ]? '='? <mf-name> | <mf-value> '<' '='? <mf-name> '<' '='? <mf-value> | <mf-value> '>' '='? <mf-name> '>' '='? <mf-value>
where 
<mf-name> = <ident>
<mf-value> = <number> | <dimension> | <ident> | <ratio>

Examples

Testing for print and screen media types

@media print {
  body { font-size: 10pt; }
}

@media screen {
  body { font-size: 13px; }
}

@media screen, print {
  body { line-height: 1.2; }
}

@media only screen
  and (min-width: 320px)
  and (max-width: 480px)
  and (resolution: 150dpi) {
    body { line-height: 1.4; }
}

Introduced in Media Queries Level 4 is a new range syntax that allows for less verbose media queries when testing for any feature accepting a range, as shown in the below examples:

@media (height > 600px) {
    body { line-height: 1.4; }
}

@media (400px <= width <= 700px) {
    body { line-height: 1.4; }
}

For more examples, please see Using media queries.

Specifications

Browser compatibility

See also

• Using media queries
• In JavaScript, @media can be accessed via the CSS object model interface CSSMediaRule.
• Extended Mozilla media features
• Extended WebKit media features