Run results for: shadow DOM vs light DOM

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:133.0) Gecko/20100101 Firefox/133.0

Browser: Firefox 133

Operating system: Ubuntu

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

shadow DOM

612K/s

light DOM

601K/s

View exact numbers

Test name	Executions per second
✓ shadow DOM	612,313 Ops/sec
light DOM	600,597 Ops/sec

HTML Preparation code:

<template id="tpl">
  <div>
	<h3>title example</h3>
    <p>example para with an <a href="#"><b>example link</b></a></p>
  </div>
</template>

<div id="container"></div>

Script Preparation code:

const tplNode = document.getElementById('tpl').content;
const container = document.getElementById('tpl');

class MyEl extends HTMLElement {
  connectedCallback() {
    this.appendChild(tplNode.cloneNode(true))
  }
}

customElements.define("my-el-lgt", MyEl);


class MyElWithShadowDOM extends HTMLElement {
  connectedCallback() {
    this.attachShadow({mode: 'open'});
    this.shadowRoot.appendChild(tplNode.cloneNode(true))
  }
}

customElements.define("my-el-shd", MyElWithShadowDOM);

Tests:

light DOM
container.innerHTML = ` <my-el-lgt></my-el-lgt> `
shadow DOM
container.innerHTML = ` <my-el-shd></my-el-shd> `