Element.namespaceURI

The Element.namespaceURI read-only property returns the namespace URI of the element, or null if the element is not in a namespace.

Before DOM4 this API was defined within the Node interface.

Syntax

namespace = element.namespaceURI

Example

In this snippet, an element is being examined for its localName and its namespaceURI. If the namespaceURI returns the XUL namespace and the localName returns "browser", then the node is understood to be a XUL <browser/>.

if (element.localName == "browser" &&
    element.namespaceURI == "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul") {
  // this is a XUL browser
}

Notes

This is not a computed value that is the result of a namespace lookup based on an examination of the namespace declarations in scope. The namespace URI of a node is frozen at the node creation time.

In Firefox 3.5 and earlier, the namespace URI for HTML elements in HTML documents is null. In later versions, in compliance with HTML5, it is http://www.w3.org/1999/xhtml as in XHTML.

You can create an element with the specified namespaceURI using the DOM Level 2 method document.createElementNS.

The DOM does not handle or enforce namespace validation per se. It is up to the DOM application to do any validation necessary. Also note that the namespace prefix, once it is associated with a particular element, cannot be changed.

Specifications

Specification Status Comment
DOM
The definition of 'Element: namespaceURI' in that specification.
Living Standard

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
namespaceURIChrome Full support 31
Notes
Full support 31
Notes
Notes This API was previously available on the Node API.
Edge Full support 17Firefox Full support 48
Notes
Full support 48
Notes
Notes This API was previously available on the Node API.
IE ? Opera Full support Yes
Notes
Full support Yes
Notes
Notes This API was previously available on the Node API.
Safari Full support 10WebView Android Full support Yes
Notes
Full support Yes
Notes
Notes This API was previously available on the Node API.
Chrome Android Full support 31
Notes
Full support 31
Notes
Notes This API was previously available on the Node API.
Firefox Android Full support YesOpera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support 2.0
Notes
Full support 2.0
Notes
Notes This API was previously available on the Node API.

Legend

Full support
Full support
Compatibility unknown
Compatibility unknown
See implementation notes.
See implementation notes.

See also