Web/API/MutationObserver

From Get docs


The MutationObserver interface provides the ability to watch for changes being made to the DOM tree. It is designed as a replacement for the older Mutation Events feature, which was part of the DOM3 Events specification.

Constructor

MutationObserver()
Creates and returns a new MutationObserver which will invoke a specified callback function when DOM changes occur.

Methods

disconnect()
Stops the MutationObserver instance from receiving further notifications until and unless observe() is called again.
observe()
Configures the MutationObserver to begin receiving notifications through its callback function when DOM changes matching the given options occur.
takeRecords()
Removes all pending notifications from the MutationObserver's notification queue and returns them in a new Array of MutationRecord objects.

Mutation Observer & customize resize event listener & demo

https://codepen.io/webgeeker/full/YjrZgg/

Example

The following example was adapted from this blog post.

// Select the node that will be observed for mutations
const targetNode = document.getElementById('some-id');

// Options for the observer (which mutations to observe)
const config = { attributes: true, childList: true, subtree: true };

// Callback function to execute when mutations are observed
const callback = function(mutationsList, observer) {
    // Use traditional 'for loops' for IE 11
    for(const mutation of mutationsList) {
        if (mutation.type === 'childList') {
            console.log('A child node has been added or removed.');
        }
        else if (mutation.type === 'attributes') {
            console.log('The ' + mutation.attributeName + ' attribute was modified.');
        }
    }
};

// Create an observer instance linked to the callback function
const observer = new MutationObserver(callback);

// Start observing the target node for configured mutations
observer.observe(targetNode, config);

// Later, you can stop observing
observer.disconnect();

Specifications

Specification Status Comment
DOMThe definition of 'MutationObserver' 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
MutationObserver

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 Full support ≤37


Full support ≤37


No support ≤37 — ≤37

Prefixed'

Prefixed' Implemented with the vendor prefix: WebKit

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

MutationObserver() constructor

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 Full support Yes


Full support Yes


No support ? — ?

Prefixed'

Prefixed' Implemented with the vendor prefix: WebKit

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

disconnect Chrome

Full support 18

Edge

Full support 12

Firefox

Full support 14

IE

Full support 11

Opera

Full support 15

Safari

Full support 6

WebView Android

Full support Yes

Chrome Android

Full support 18

Firefox Android

Full support 14

Opera Android

Full support 14

Safari iOS

Full support 6

Samsung Internet Android

Full support 1.0

observe Chrome

Full support 18

Edge

Full support 12

Firefox

Full support 14

IE

Full support 11

Opera

Full support 15

Safari

Full support 6

WebView Android

Full support ≤37

Chrome Android

Full support 18

Firefox Android

Full support 14

Opera Android

Full support 14

Safari iOS

Full support 6

Samsung Internet Android

Full support 1.0

takeRecords Chrome

Full support 18

Edge

Full support 12

Firefox

Full support 14

IE

Full support 11

Opera

Full support 15

Safari

Full support 6

WebView Android

Full support Yes

Chrome Android

Full support 18

Firefox Android

Full support 14

Opera Android

Full support 14

Safari iOS

Full support 6

Samsung Internet Android

Full support 1.0

Legend

Full support  
Full support
Requires a vendor prefix or different name for use.'
Requires a vendor prefix or different name for use.


See also