CSS - max-width

The max-width CSS descriptor specifies the maximum width of the viewport of a document defined via the @viewport at-rule.

Syntax  

CSS
/* Keyword value */
max-width auto;

/* <length> values */
max-width: 600px;
max-width: 80em;
max-width: 15cm;

/* <percentage> value */
max-width: 75%;

Values

auto
The used value is calculated from the other CSS descriptors' values.
<length>
A non-negative absolute or relative length.
<percentage>
A percentage value relative to the width of the initial viewport at zoom factor 1.0 for horizontal lengths. Must be non-negative.

Formal syntax

CSS
<a href="css/@viewport/max-width#viewport-length"><viewport-length></a><p>where <br><code><viewport-length> = auto <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> <a href="css/@viewport/max-width#length-percentage"><length-percentage></a></code></p><p>where <br><code><length-percentage> = <a title="Possible values: a number followed by'em', 'ex', 'ch', 'rem', 'px', 'cm', 'mm', 'in', 'vh', 'vw', 'vmin', 'vmax', 'pt', 'pc' or 'px', like 3px, 1.5cm, -0.5em or 0" href="css/length"><length></a> <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> <a title="" href="css/percentage"><percentage></a></code></p>

Description  

The max-width CSS descriptor specifies the maximum width of the viewport of a document defined via the @viewport at-rule.

By default, the width is set as close as possible to the initial viewport considering the maximum width constraint.

Related at-rule@viewport
Initial valueauto
Percentagesrefer to the width of the initial viewport
Mediavisual, continuous
Computed valueif specified as a length, the corresponding absolute length; if specified as a percentage, the specified value; otherwise, auto
Canonical orderthe unique non-ambiguous order defined by the formal grammar

Browser Compatibility  

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 29 (behind a flag) No support 10 -ms 11.10
Removed in 15
Reintroduced behind a flag in 16		 No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 4.4 29 No support 10-ms 11.10
Removed in 15
Reintroduced behind a flag in 16		 No support

Specifications  

Specification Status Comment
CSS Device Adaptation
The definition of '"max-width" descriptor' in that specification.		 Working Draft Initial definition

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/css/@viewport/max-width

@viewport CSS CSS Descriptor Reference