JSFiddle - React, Tailwind, and code Playground

JavaScript

function addElements(count) {
    for (var i = 0; i < count; ++i) {
        document.body.appendChild(document.createElement('div'));
    }
}

function measure(count) {
    addElements(count);
    var t = Date.now();
    document.body.offsetTop;
    return Date.now() - t;
}

var result = '';

var N1 = 50000;
result = N1 + ': ';
document.body.textContent = result;

var time1 = measure(N1);
result += time1;
document.body.textContent = result;

var N2 = 10 * N1;
result += ' ' + N2 + ': ';
document.body.textContent = result;

var time2 = measure(N2);
result += time2 + ' factor: ' + (time2 / time1);
document.body.textContent = result;