Run results for: innerHTML vs insertAdjacentHTML vs appendChild vs append vs insertAdjacentElement

Test name	Executions per second
✓ insertAdjacentHTML	168,463 Ops/sec
innerHTML	155,660 Ops/sec
appendChild	79,632 Ops/sec
insertAdjacentElement	76,450 Ops/sec
append	67,263 Ops/sec

innerHTML

const box = document.createElement('div');
let html = '';
for (let i = 0; i < repeat; i++)
  html += '<div class="a b"><div>Test</div></div>';
box.innerHTML += html;

insertAdjacentHTML

const box = document.createElement('div');
let html = '';
for (let i = 0; i < repeat; i++)
  html += '<div class="a b"><div>Test</div></div>';
box.insertAdjacentHTML('beforeend', html);

appendChild

const box = document.createElement('div');
const els = [];
for (let i = 0; i < repeat; i++) {
  const div2 = document.createElement('div');
  div2.innerText = 'Test';
  const div1 = document.createElement('div');
  div1.className = 'a b';
  div1.appendChild(div2);
  els.push(div1);
}
els.forEach(el => box.appendChild(el));

append

const box = document.createElement('div');
const els = [];
for (let i = 0; i < repeat; i++) {
  const div2 = document.createElement('div');
  div2.innerText = 'Test';
  const div1 = document.createElement('div');
  div1.className = 'a b';
  div1.append(div2);
  els.push(div1);
}
box.append(...els);

insertAdjacentElement

const box = document.createElement('div');
const els = [];
for (let i = 0; i < repeat; i++) {
  const div2 = document.createElement('div');
  div2.innerText = 'Test';
  const div1 = document.createElement('div');
  div1.className = 'a b';
  div1.insertAdjacentElement('beforeend', div2);
  els.push(div1);
}
els.forEach(el => box.insertAdjacentElement('beforeend', el));