MutationRecord

BaselineWidely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

TheMutationRecord is a read-only interface that represents an individual DOM mutation observed by aMutationObserver. It is the object inside the array passed to the callback of aMutationObserver.

Instance properties

MutationRecord.addedNodesRead only

The nodes added by a mutation. Will be an emptyNodeList if no nodes were added.

MutationRecord.attributeNameRead only

The name of the changed attribute as a string, ornull.

MutationRecord.attributeNamespaceRead only

The namespace of the changed attribute as a string, ornull.

MutationRecord.nextSiblingRead only

The next sibling of the added or removed nodes, ornull.

MutationRecord.oldValueRead only

The value depends on theMutationRecord.type:

Forattributes, it is the value of the changed attribute before the change.
ForcharacterData, it is the data of the changed node before the change.
ForchildList, it isnull.

MutationRecord.previousSiblingRead only

The previous sibling of the added or removed nodes, ornull.

MutationRecord.removedNodesRead only

The nodes removed by a mutation. Will be an emptyNodeList if no nodes were removed.

MutationRecord.targetRead only

The node the mutation affected, depending on theMutationRecord.type.

Forattributes, it is the element whose attribute changed.
ForcharacterData, it is theCharacterData node.
ForchildList, it is the node whose children changed.

MutationRecord.typeRead only

A string representing the type of mutation:attributes if the mutation was an attribute mutation,characterData if it was a mutation to aCharacterData node, andchildList if it was a mutation to the tree of nodes.