JSFiddle - React, Tailwind, and code Playground

HTML

<ul></ul>

CSS

li {
  width: 10px;
  height: 10px;
  background: red;
  padding: 10px;
}

JavaScript

const ul = document.querySelector('ul');

const fragment = document.createDocumentFragment();

for (var i=0; i<2000; i++) {
	fragment.append(document.createElement('li'));
}

ul.append(fragment);