contain

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Summary

The contain property allows an author to indicate that an element and its contents are, as much as possible, independent of the rest of the document tree. This allows the browser to recalculate layout, style, paint, size, or any combination of them for a limited area of the DOM and not the entire page. This property is useful on pages that contain a lot of widgets that are all independent as it can be used to prevent one widget's CSS rules from changing other things on the page.

Initial valuenone
Applies toall elements
Inheritedfalse
Mediaall
Computed valueas specified
Animation typediscrete
Canonical orderper grammar

Syntax

/* No layout containment. */
contain: none;

/* Turn on containment for layout, style, paint, and size. */
contain: strict;

/* Turn on containment for layout, style, and paint. */
contain: content;

/* Turn on size containment for an element. */
contain: size;

/* Turn on layout containment for an element. */
contain: layout;

/* Turn on style containment for an element. */
contain: style;

/* Turn on paint containment for an element. */
contain: paint;

Values

none
Indicates the element renders as normal, with no containment applied.
strict
Indicates that all containment rules are applied to the element. This is equivalent to contain: size layout style paint.
content
Indicates that all containment rules except size are applied to the element. This is equivalent to contain: layout style paint.
size
Indicates that the element can be sized without the need to examine its dependants for size changes.
layout
Indicates that nothing outside the element may affect its internal layout and vice versa. 
style
Indicates that, for properties that can have effects on more than just an element and its descendants, those effects don't escape the containing element.
paint
Indicates that descendents of the element don't display outside its bounds. If an element is off-screen or otherwise not visible, it's descendants are also guaranteed to not be visible.

Formal syntax

none | strict | content | [ size || layout || style || paint ]

Specifications

Specification Status Comment
CSS Containment Module Level 3 Editor's Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 52.0 No support[1] ? 40 ?
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support No support 52.0 No support[1] ? ? 40 ? 52.0

[1] This feature is not implemented yet. See bug 1150081.

Document Tags and Contributors

 Contributors to this page: Siilwyn, asensoy, Sebastianz, xiaody, jpmedley
 Last updated by: Siilwyn,