Run results for: replaceChild vs replaceChildren vs documentFragment

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.5 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.5

Device Platform: Mobile

Date tested: one year ago

replaceChild

4.2M/s

replaceChildren

3.6M/s

append documentFragment

1.8M/s

View exact numbers

Test name	Executions per second
✓ replaceChild	4,168,237 Ops/sec
replaceChildren	3,620,627 Ops/sec
append documentFragment	1,846,210 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)