transform-box

The transform-box CSS property defines the layout box to which the transform and transform-origin properties relate.

/* Keyword values */
transform-box: content-box;
transform-box: border-box;
transform-box: fill-box;
transform-box: stroke-box;
transform-box: view-box;

/* Global values */
transform-box: inherit;
transform-box: initial;
transform-box: unset;

Syntax

The transform-box property is specified as one of the keyword values listed below.

Values

content-box

The content box is used as the reference box. The reference box of a <table> is the border box of its table wrapper box, not its table box.

border-box
The border box is used as the reference box. The reference box of a <table> is the border box of its table wrapper box, not its table box.
fill-box
The object bounding box is used as the reference box.
stroke-box
The stroke bounding box is used as the reference box.
view-box
The nearest SVG viewport is used as the reference box. If a viewBox attribute is specified for the SVG viewport creating element, the reference box is positioned at the origin of the coordinate system established by the viewBox attribute, and the dimension of the reference box is set to the width and height values of the viewBox attribute.

Formal definition

Initial valueview-box
Applies totransformable elements
Inheritedno
Computed valueas specified
Animation typediscrete

Formal syntax

content-box | border-box | fill-box | stroke-box | view-box

Examples

SVG transform-origin scoping

In this example we have an SVG:

<svg id="svg" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 50 50">
  <g>
    <circle id="center" fill="red" r="1" transform="translate(25 25)" />
    <circle id="boxcenter" fill="blue" r=".5" transform="translate(15 15)" />
    <rect id="box" x="10" y="10" width="10" height="10" rx="1" ry="1" stroke="black" fill="none" />
  </g>
</svg>

In the CSS we have an animation that uses a transform to rotate the rectangle infinitely. transform-box: fill-box is used to make the the transform-origin the center of the bounding box, so the rectangle spins in place. Without it, the transform origin is the center of the SVG canvas, and so you get a very different effect.

svg{
  width:80vh;
  border:1px solid #d9d9d9;
  position:absolute;
  margin: auto;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
}

#box{
  transform-origin:50% 50%;
  /*+++++++++++++++++++++++++++*/
  /* if I remove this rule the pen won't work properly on Chrome for Mac, FF, Safari
  Will still work properly on Chrome for PC & Opera*/
  transform-box: fill-box;
  /*Alternatively  I can use transform-origin:15px 15px;*/
  /*+++++++++++++++++++++++++++*/
  animation: rotateBox 3s linear infinite;
}

@keyframes rotateBox {
  to {
    transform: rotate(360deg);
  }

Full credit for this example goes to Pogany; see this codepen for a live version.

Specifications

Specification Status Comment
CSS Transforms Level 1
The definition of 'transform-box' in that specification.
Working Draft Initial definition

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
transform-boxChrome Full support 64Edge Full support 79Firefox Full support 55
Full support 55
Full support 43
Disabled
Disabled From version 43: this feature is behind the svg.transform-box.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
No support 41 — 43
Disabled
Disabled From version 41 until version 43 (exclusive): this feature is behind the svg.transform-origin.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 51Safari Full support 11WebView Android Full support 64Chrome Android Full support 64Firefox Android Full support 55
Full support 55
Full support 43
Disabled
Disabled From version 43: this feature is behind the svg.transform-box.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
No support 41 — 43
Disabled
Disabled From version 41 until version 43 (exclusive): this feature is behind the svg.transform-origin.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 47Safari iOS Full support 11Samsung Internet Android Full support 9.0

Legend

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

See also