Web/API/Node/compareDocumentPosition

The Node.compareDocumentPosition() method reports the position of the given node relative to another node in any document — not just the given node’s document.

The return value is a bitmask of the following values:

Name	Value
`DOCUMENT_POSITION_DISCONNECTED`	1
`DOCUMENT_POSITION_PRECEDING`	2
`DOCUMENT_POSITION_FOLLOWING`	4
`DOCUMENT_POSITION_CONTAINS`	8
`DOCUMENT_POSITION_CONTAINED_BY`	16
`DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC`	32

Syntax

compareMask = node.compareDocumentPosition(otherNode)

Parameters

otherNode: The other Node with which to compare the first node’s document position.

Return value

An integer value whose bits represent the otherNode's relationship to the calling node.

More than one bit is set if multiple scenarios apply. For example, if otherNode is located earlier in the document and contains the node on which compareDocumentPosition() was called, then both the DOCUMENT_POSITION_CONTAINS and DOCUMENT_POSITION_PRECEDING bits would be set, producing a value of 10 (0x0A).

Example

const head = document.head;
const body = document.body;

if (head.compareDocumentPosition(body) & Node.DOCUMENT_POSITION_FOLLOWING) {
  console.log('Well-formed document');
} else {
  console.error('<head> is not before <body>');
}

Note: Because the result returned by ' compareDocumentPosition() is a bitmask, the bitwise AND operator must be used for meaningful results.

Specifications

Specification	Status	Comment
DOMThe definition of 'Node.compareDocumentPosition()' in that specification.	Living Standard
Document Object Model (DOM) Level 3 Core SpecificationThe definition of 'Node.compareDocumentPosition()' in that specification.	Obsolete	Initial definition

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`compareDocumentPosition`	Chrome Full support Yes	Edge Full support 12	Firefox Full support 9	IE Full support 9 Notes' Full support 9 Notes' Notes' Only supports `contains` for elements	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support 9	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes

Legend

Full support: Full support
See implementation notes.': See implementation notes.