Run results for: replaceChild vs replaceChildren vs documentFragment

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:99.0) Gecko/20100101 Firefox/99.0

Browser: Firefox 99

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
replaceChild	916877.8 Ops/sec
replaceChildren	579288.5 Ops/sec
append documentFragment	22791.9 Ops/sec

HTML Preparation code:

<div id="container"></div>

Script Preparation code:

var elements = [document.createElement('div'), document.createElement('div')];
var fragment = document.createDocumentFragment();
var container = document.getElementById('container');

elements.forEach(element => fragment.appendChild(element));
container.appendChild(fragment);

Tests:

replaceChild
var changeIndex = 1; elements[changeIndex] = document.createElement('div'); container.replaceChild(elements[changeIndex], container.children[changeIndex]);
replaceChildren
var changeIndex = 1; elements[changeIndex] = document.createElement('div'); container.replaceChildren(elements)
append documentFragment
var changeIndex = 1; var newChildren = document.createDocumentFragment(); elements[changeIndex] = document.createElement('div'); elements.forEach(element => newChildren.appendChild(element)); while(container.firstChild) { container.firstChild.remove(); } container.appendChild(newChildren)

Run results for: replaceChild vs replaceChildren vs documentFragment

replaceChild

replaceChildren

append documentFragment