Run results for: insertAdjacentHTML vs append

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:89.0) Gecko/20100101 Firefox/89.0

Browser: Firefox 89

Operating system: Windows 7

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
append	253.9 Ops/sec
insertAdjacentHTML	935.2 Ops/sec

HTML Preparation code:

<div id="test"></div>

Tests:

append
var newElement = document.createElement("div"); newElement.id = "testing" for (i = 0; i < 1000; i++) { var newElementPart = document.createElement("div"); newElementPart.classList.add("testClass"); newElement.append(newElementPart); } document.getElementById("test").append(newElement);
insertAdjacentHTML
html = "<div id='testing'>" for (i = 0; i < 1000; i++) { html += "<div class='testClass'></div>"; } html += "</div>"; document.getElementById("test").insertAdjacentHTML("beforeend", html);