Run results for: Creating elements with cloneNode (template vs. normal element)

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0

Browser: Firefox 88

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Simple - Template	442529.0 Ops/sec
Simple - JavaScript	719958.2 Ops/sec
Complex - Template	123095.6 Ops/sec
Complex - JavaScript	183532.9 Ops/sec

Script Preparation code:

var simpleTemplate = document.createElement("template");
simpleTemplate.innerHTML = `<span class="simple"></span>`;
  
var complexTemplate = document.createElement("template");
complexTemplate.innerHTML =
  `<span class="complex">
     <span class="simple-1"></span>
     <span class="simple-2">
       <span class="simple-2-1"></span>
     </span>
     <span class="simple-3">
       <span class="simple-3-1"></span>
     </span>
     <span class="simple-4"></span>
   </span>`;

var simpleElement = document.createElement("span");
simpleElement.classList.add("simple");
  
var complexElement = document.createElement("span");
complexElement.classList.add("complex");
complexElement.innerHTML =
  `<span class="simple-1"></span>
   <span class="simple-2">
     <span class="simple-2-1"></span>
   </span>
   <span class="simple-3">
     <span class="simple-3-1"></span>
   </span>
   <span class="simple-4"></span>`;

Tests:

Simple - Template
let el = document.createElement("div"); let content = simpleTemplate.content.cloneNode(true); el.appendChild(content);
Simple - JavaScript
let el = document.createElement("div"); let content = simpleElement.cloneNode(true); el.appendChild(content);
Complex - Template
let el = document.createElement("div"); let content = complexTemplate.content.cloneNode(true); el.appendChild(content);
Complex - JavaScript
let el = document.createElement("div"); let content = complexElement.cloneNode(true); el.appendChild(content);

Run results for: Creating elements with cloneNode (template vs. normal element)

Simple - Template

Simple - JavaScript

Complex - Template

Complex - JavaScript