Size containment
The contain: size CSS declaration sets an element's dimensions exclusively by its height and width properties, ignoring its contents and descendants. This permits the browser to avoid slower layout calculations.
Browser support
| Feature | Desktop | Mobile | ||||
|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Safari | Chrome Android | Safari iOS | |
css.properties.contain.size | 52 | 79 | 69 | 15.4 | 52 | 15.4 |
1+Supported (version) Not supported ※Has note Sub-feature descriptions sourced from MDN Web Docs (CC BY-SA 2.5)
Syntax
CSS
.fixed-widget {
contain: size;
width: 300px;
height: 200px;
}Live demo
Use cases
-
Using Size containment
The contain: size CSS declaration sets an element's dimensions exclusively by its height and width properties, ignoring its contents and descendants. This permits the browser to avoid slower layout calculations.
Cautions
- May not be supported in older browsers.
Accessibility
- Make sure visual changes are conveyed appropriately to assistive technology.