@namespaceBaseline · Widely available
The @namespace CSS rule sets a default namespace or namespace prefix. Namespace prefixes allow CSS selectors to distinguish elements with the same name but different document types, such as the HTML <a> element and the SVG <a> element.
Supported in all major browsers for at least 30 months — safe to use without fallbacks. Baseline since Jul 29, 2015. Widely available since Jan 29, 2018.
Browser support
DesktopChrome
1+Supportedsince Dec 11, 2008
Current: 155Edge
12+Supportedsince Jul 29, 2015
Current: 154Firefox
1+Supportedsince Nov 9, 2004
Current: 157Safari
1+Supportedsince Jun 23, 2003
Current: 27MobileChrome Android
18+Supportedsince Jun 27, 2012
Current: 155Firefox Android
4+Supportedsince Mar 29, 2011
Current: 157Safari iOS
1+Supportedsince Jun 29, 2007
Current: 27How to use
This feature is Baseline widely available — use it freely, no fallback needed.
Example
Full syntax and examples are on MDN: CSSNamespaceRule.
Feature detection
CSS · check before using
@supports selector(:namespace) {
/* styles that use :namespace */
}
/* or in JavaScript */
if (CSS.supports("selector(:namespace)")) {
// use it
}Documentation (MDN)
Specification
Usage share
Sub-features
Support for each part of the feature (5). The overall table above shows when the whole feature works.
| Sub-feature | Chrome | Edge | Firefox | Safari | Chrome Android | Firefox Android | Safari iOS |
|---|---|---|---|---|---|---|---|
| CSSNamespaceRule | 47 | 12 | 53 | 10.1 | 47 | 53 | 10.3 |
| CSSNamespaceRule.namespaceURI | 47 | 12 | 59 | 10.1 | 47 | 59 | 10.3 |
| CSSNamespaceRule.prefix | 47 | 12 | 59 | 10.1 | 47 | 59 | 10.3 |
| @namespace | 1 | 12 | 1 | 1 | 18 | 4 | 1 |
| namespace | 1 | 12 | 1 | 3 | 18 | 4 | 1 |