This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The inline-size CSS property defines the horizontal or vertical size of an element's block, depending on its writing mode. It corresponds to either the width or the height property, depending on the value of writing-mode.

Syntax

/* <length> values */
inline-size: 300px;
inline-size: 25em;

/* <percentage> values */
inline-size: 75%;

/* Keyword values */
inline-size: 25em border-box;
inline-size: 75% content-box;
inline-size: max-content;
inline-size: min-content;
inline-size: available;
inline-size: fit-content;
inline-size: auto;

/* Global values */
inline-size: inherit;
inline-size: initial;
inline-size: unset;

If the writing mode is vertically oriented, the value of inline-size relates to the height of the element; otherwise, it relates to the width of the element. A related property is block-size, which defines the other dimension of the element.

Initial valueauto
Applies tosame as width and height
Inheritedno
Percentagesinline-size of containing block
Mediavisual
Computed valuesame as width and height
Animation typediscrete
Canonical orderthe unique non-ambiguous order defined by the formal grammar

Values

The inline-size property takes the same values as the width and height properties.

Formal syntax

<'width'>

Example

HTML

<p class="exampleText">Example text</p>

CSS

.exampleText {
  writing-mode: vertical-rl;
  background-color: yellow;
  inline-size: 110px;
}

Specification

Specification Status Comment
CSS Logical Properties and Values Level 1
The definition of 'inline-size' in that specification.
Editor's Draft Initial definition

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic supportChrome Full support 57Edge No support NoFirefox Full support 41
Full support 41
No support 38 — 51
Disabled
Disabled From version 38 until version 51 (exclusive): this feature is behind the layout.css.vertical-text.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 44Safari No support NoWebView Android Full support 57Chrome Android Full support 57Edge Mobile No support NoFirefox Android Full support 41
Full support 41
No support 38 — 51
Disabled
Disabled From version 38 until version 51 (exclusive): this feature is behind the layout.css.vertical-text.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 44Safari iOS No support NoSamsung Internet Android No support No

Legend

Full support  
Full support
No support  
No support
User must explicitly enable this feature.
User must explicitly enable this feature.

See also

Document Tags and Contributors

Last updated by: rachelandrew,