Web/API/MutationObserverInit/characterData

The MutationObserverInit dictionary's optional characterData property is used to specify whether or not to monitor the node or nodes being observed for changes to their textual contents.

Character data changes are detectable on any text node, including nodes based on the Text, ProcessingInstruction, and Comment interfaces.

Note that this doesn't monitor content of an HTMLElement, even if it only contains text inside, as it only monitors text nodes themselves. So either pass directly a text node to the observe() method or you need to also set subtree: true.

Syntax

var options = {
  characterData: true | false
}

Value

A Boolean value indicating whether or not to call the observer's callback function when textual nodes' values change.

If true, the callback specified when observe() was used to start observing the node or subtree is called any time the contents of a text node are changed.

You can expand the capabilities of attribute mutation monitoring using other options:

characterDataOldValue lets you specify whether or not you want the previous value of changed text nodes to be provided using the MutationRecord's oldValue property.
subtree lets you specify whether to watch the target node and all of its descendants (true), or just the target node (false).

If you set characterDataOldValue to true, characterData is automatically assumed to be true, even if you don't expressly set it as such.

Example

Specifications

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

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
`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

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