We're looking for a person or people to help audit MDN to find places we could speed up. Is this you or someone you know? Check out the RFP: https://mzl.la/2IHcMiE

この記事はまだボランティアによって 日本語 に翻訳されていません。ぜひ MDN に参加して翻訳を手伝ってください!
この記事を English (US) で読むこともできます。

Creates an element with the specified namespace URI and qualified name.

To create an element without specifying a namespace URI, use the createElement method.


var element = document.createElementNS(namespaceURI, qualifiedName[, options]);


A string that specifies the namespace URI to associate with the element. The namespaceURI property of the created element is initialized with the value of namespaceURI. See Valid Namespace URIs.
A string that specifies the type of element to be created. The nodeName property of the created element is initialized with the value of qualifiedName.
An optional ElementCreationOptions object containing a single property named is, whose value is the tag name for a custom element previously defined using customElements.define(). For backwards compatibility with previous versions of the Custom Elements specification, some browsers will allow you to pass a string here instead of an object, where the string's value is the custom element's tag name. See Extending native HTML elements for more information on how to use this parameter.
The new element will be given an is attribute whose value is the custom element's tag name. Custom elements are an experimental feature only available in some browsers.

Return value

The new Element.

Valid Namespace URIs

  • HTML - Use http://www.w3.org/1999/xhtml
  • SVG - Use http://www.w3.org/2000/svg
  • XBL - Use http://www.mozilla.org/xbl
  • XUL - Use http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul


This creates a new <div> element in the XHTML namespace and appends it to the vbox element. Although this is not an extremely useful XUL document, it does demonstrate the use of elements from two different namespaces within a single document:

<?xml version="1.0"?>
<page xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
      title="||Working with elements||"

<script type="text/javascript"><![CDATA[
 var container;
 var newdiv;
 var txtnode;

 function init(){
   container = document.getElementById("ContainerBox");
   newdiv = document.createElementNS("http://www.w3.org/1999/xhtml","div");
   txtnode = document.createTextNode("This is text that was constructed dynamically with createElementNS and createTextNode then inserted into the document using appendChild.");


 <vbox id='ContainerBox' flex='1'>
   The script on this page will add dynamic content below:


The example given above uses inline script which is not recommended in XHTML documents. This particular example is actually an XUL document with embedded XHTML, however, the recommendation still applies.


Specification Status Comment
The definition of 'Document.createElement' in that specification.
Living Standard  

Browser compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)
options argument (Yes)[1] No support 50 (50)[2][3] ? ? ?
Feature Android Edge Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

[1] In previous versions of the specification, this argument was just a string whose value was the custom element's tag name. For the sake of backwards compatibility, Chrome accepts both forms.

[2] See [1] above: like Chrome, Firefox accepts a string instead of an object here, but only from version 51 onwards. In version 50,  options must be an object.

[3] To experiment with custom elements in Firefox, you must set the dom.webcomponents.enabled and dom.webcomponents.customelements.enabled preferences to true.

See also


 最終更新者: dunnbobcat,