Web/API/MutationObserverInit

The MutationObserverInit dictionary describes the configuration of a mutation observer. As such, it's primarily used as the type of the options parameter on the MutationObserver.observe() method.

Properties

At a minimum, one of childList, attributes, and/or characterData must be true when you call observe(). Otherwise, a TypeError exception will be thrown.

subtree Optional

Set to true to extend monitoring to the entire subtree of nodes rooted at target. All of the other MutationObserverInit properties are then extended to all of the nodes in the subtree instead of applying solely to the target node. The default value is false.

childList Optional

Set to true to monitor the target node (and, if subtree is true, its descendants) for the addition of new child nodes or removal of existing child nodes. The default value is false.

attributes Optional

Set to true to watch for changes to the value of attributes on the node or nodes being monitored. The default value is true if either of attributeFilter or attributeOldValue is specified, otherwise the default value is false.

attributeFilter Optional

An array of specific attribute names to be monitored. If this property isn't included, changes to all attributes cause mutation notifications.

attributeOldValue Optional

Set to true to record the previous value of any attribute that changes when monitoring the node or nodes for attribute changes; see Monitoring attribute values in MutationObserver for details on watching for attribute changes and value recording. The default value is false.

characterData Optional

Set to true to monitor the specified target node (and, if subtree is true, its descendants) for changes to the character data contained within the node or nodes. The default value is true if characterDataOldValue is specified, otherwise the default value is false.

characterDataOldValue Optional

Set to true to record the previous value of a node's text whenever the text changes on nodes being monitored. For details and an example, see Monitoring text content changes in MutationObserver. The default value is false.

Specifications

Specification	Status	Comment
DOMThe definition of 'MutationObserverInit' in that specification.	Living Standard

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

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
MutationObserverInit	Chrome Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support 12	Firefox Full support 14	IE Full support 11	Opera Full support 15	Safari Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	WebView Android ?	Chrome Android Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Firefox Android Full support 14	Opera Android Full support 14	Safari iOS Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.0 — 1.5 Prefixed' Prefixed' Implemented with the vendor prefix: webkit
attributeFilter	Chrome Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support 12 Notes' Full support 12 Notes' Notes' Before Edge 79, this requires attributes: true when using attributeFilter. If attributes: true is not present, then Edge throws a syntax error.	Firefox Full support 14	IE Full support 11 Notes' Full support 11 Notes' Notes' Internet Explorer requires attributes: true when using attributeFilter. If attributes: true is not present, then Internet Explorer throws a syntax error.	Opera Full support 15	Safari Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	WebView Android ?	Chrome Android Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Firefox Android Full support 14	Opera Android Full support 14	Safari iOS Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.0 — 1.5 Prefixed' Prefixed' Implemented with the vendor prefix: webkit
attributeOldValue	Chrome Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support 12	Firefox Full support 14 Notes' Full support 14 Notes' Notes' Starting in Firefox 36, attributeOldValue has no default value; previously, its default value was false.	IE Full support 11	Opera Full support 15	Safari Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	WebView Android ?	Chrome Android Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Firefox Android Full support 14 Notes' Full support 14 Notes' Notes' Starting in Firefox 36, attributeOldValue has no default value; previously, its default value was false.	Opera Android Full support 14	Safari iOS Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.0 — 1.5 Prefixed' Prefixed' Implemented with the vendor prefix: webkit
attributes	Chrome Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support 12	Firefox Full support 14 Notes' Full support 14 Notes' Notes' Starting in Firefox 36, attributes has no default value; previously, its default value was false.	IE Full support 11	Opera Full support 15	Safari Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	WebView Android ?	Chrome Android Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Firefox Android Full support 14 Notes' Full support 14 Notes' Notes' Starting in Firefox 36, attributes has no default value; previously, its default value was false.	Opera Android Full support 14	Safari iOS Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.0 — 1.5 Prefixed' Prefixed' Implemented with the vendor prefix: webkit
characterData	Chrome Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support 12	Firefox Full support 14 Notes' Full support 14 Notes' Notes' Starting in Firefox 36, characterData has no default value; previously, its default value was false.	IE Full support 11	Opera Full support 15	Safari Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	WebView Android ?	Chrome Android Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Firefox Android Full support 14 Notes' Full support 14 Notes' Notes' Starting in Firefox 36, characterData has no default value; previously, its default value was false.	Opera Android Full support 14	Safari iOS Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.0 — 1.5 Prefixed' Prefixed' Implemented with the vendor prefix: webkit
characterDataOldValue	Chrome Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support 12	Firefox Full support 14 Notes' Full support 14 Notes' Notes' Starting in Firefox 36, characterDataOldValue has no default value; previously, its default value was false.	IE Full support 11	Opera Full support 15	Safari Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	WebView Android ?	Chrome Android Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Firefox Android Full support 14 Notes' Full support 14 Notes' Notes' Starting in Firefox 36, characterDataOldValue has no default value; previously, its default value was false.	Opera Android Full support 14	Safari iOS Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.0 — 1.5 Prefixed' Prefixed' Implemented with the vendor prefix: webkit
childList	Chrome Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support 12	Firefox Full support 14	IE Full support 11	Opera Full support 15	Safari Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	WebView Android ?	Chrome Android Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Firefox Android Full support 14	Opera Android Full support 14	Safari iOS Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.0 — 1.5 Prefixed' Prefixed' Implemented with the vendor prefix: webkit
subtree	Chrome Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support 12	Firefox Full support 14	IE Full support 11	Opera Full support 15	Safari Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	WebView Android ?	Chrome Android Full support 26 Full support 26 No support 18 — 26 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Firefox Android Full support 14	Opera Android Full support 14	Safari iOS Full support 7 Full support 7 No support 6 — 7 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.0 — 1.5 Prefixed' Prefixed' Implemented with the vendor prefix: webkit

Legend

Full support  

Full support

Compatibility unknown  

Compatibility unknown

See implementation notes.'

See implementation notes.

Requires a vendor prefix or different name for use.'

Requires a vendor prefix or different name for use.

MutationObserverInit by Mozilla Contributors is licensed under CC-BY-SA 2.5.