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

The inset-block CSS property defines the logical block start and end offsets of an element, which maps to physical offsets depending on the element's writing mode, directionality, and text orientation. It corresponds to the top and bottom, or right and left properties depending on the values defined for writing-mode, direction, and text-orientation.

/* <length> values */
inset-block: 3px 10px;
inset-block: 2.4em 3em;
inset-block: 10px; /* value applied to start and end */

/* <percentage>s of the width or height of the containing block */
inset-block: 10% 5%;

/* Keyword value */
inset-block: auto;

/* Global values */
inset-block: inherit;
inset-block: initial;
inset-block: unset;

The shorthand for the other dimension is  inset-inline, which is a shorthand for inset-inline-start, and inset-inline-end.

Initial valueauto
Applies topositioned elements
Percentageslogical-height of containing block
Computed valuesame as box offsets: top, right, bottom, left properties except that directions are logical
Animation typea length, percentage or calc();
Canonical orderthe unique non-ambiguous order defined by the formal grammar



The inset-block property takes the same values as the left property.

Formal syntax



HTML Content

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

CSS Content

div {
  background-color: yellow;
  width: 120px;
  height: 120px;

.exampleText {
  writing-mode: vertical-lr;
  position: relative;
  inset-block: 20px 50px;
  background-color: #c8c800;


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

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic support
Chrome No support NoEdge No support NoFirefox No support NoIE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoEdge Mobile No support NoFirefox Android No support NoOpera Android No support NoSafari iOS No support NoSamsung Internet Android No support No


No support  
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

See also

Document Tags and Contributors

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Last updated by: mdnwebdocs-bot,