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

MutationRecord.addedNodes Read only

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

MutationRecord.attributeName Read only

The name of the changed attribute as a string, or null.

MutationRecord.attributeNamespace Read only

The namespace of the changed attribute as a string, or null.

MutationRecord.nextSibling Read only

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

MutationRecord.oldValue Read only

The value depends on the MutationRecord.type:

• For attributes, it is the value of the changed attribute before the change.
• For characterData, it is the data of the changed node before the change.
• For childList, it is null.

MutationRecord.previousSibling Read only

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

MutationRecord.removedNodes Read only

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

MutationRecord.target Read only

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

• For attributes, it is the element whose attribute changed.
• For characterData, it is the CharacterData node.
• For childList, it is the node whose children changed.

MutationRecord.type Read only

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