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document.importNode

Creates a copy of a node from an external document that can be inserted into the current document.

Syntax

var node = document.importNode(externalNode, deep);

node: The new node that is imported into the document. The new node's parentNode is null, since it has not yet been inserted into the document tree.
externalNode: The node from another document to be imported.
deep: A boolean, indicating whether the descendants of the imported node need to be imported.

Note: In the DOM4 specification (as implemented in Gecko 13.0 (Firefox 13 / Thunderbird 13 / SeaMonkey 2.10)), deep is an optional argument. If omitted, the method acts as if the value of deep was true, defaulting to using deep cloning as the default behavior. To create a shallow clone, deep must be set to false.

This behavior has been changed in the latest spec, and if omitted, the method will act as if the value of deep was false. Though It's still optional, you should always provide the deep argument both for backward and forward compatibility. With Gecko 28.0 (Firefox 28 / Thunderbird 28 / SeaMonkey 2.25 / Firefox OS 1.3), the console warned developers not to omit the argument. Starting with Gecko 29.0 (Firefox 29 / Thunderbird 29 / SeaMonkey 2.26)), a shallow clone is defaulted instead of a deep clone.

Example

var iframe = document.getElementsByTagName("iframe")[0];
var oldNode = iframe.contentWindow.document.getElementById("myNode");
var newNode = document.importNode(oldNode, true);
document.getElementById("container").appendChild(newNode);

Notes

The original node is not removed from the original document. The imported node is a clone of the original.

Nodes from external documents should be cloned using document.importNode() (or adopted using document.adoptNode()) before they can be inserted into the current document. For more on the Node.ownerDocument issues, see the W3C DOM FAQ.

Firefox doesn't currently enforce this rule (it did for a while during the development of Firefox 3, but too many sites break when this rule is enforced). We encourage Web developers to fix their code to follow this rule for improved future compatibility.

Specifications

Specification	Status	Comment
DOM The definition of 'document.importNode()' in that specification.	Living Standard
Document Object Model (DOM) Level 2 Core Specification The definition of 'document.importNode()' in that specification.	Recommendation	Initial definition

Browser compatibility

Feature	Chrome	Edge	Firefox (Gecko)	Internet Explorer	Opera	Safari
DOM 2 version	(Yes)	(Yes)	1.0 (1.7 or earlier)	9.0	9.0	(Yes)
DOM 4 version (`deep` optional)	(Yes)	No support	10 (10)	No support	No support	Nightly build