// stats.js: JavaScript Performance Monitor
const stats = new Stats();
stats.showPanel(0); // 0: fps, 1: ms, 2: mb, 3+: custom
document.body.appendChild(stats.dom);
function animate () {
    stats.begin();
    // monitored code goes here
    stats.end();

    requestAnimationFrame(animate);
}
requestAnimationFrame(animate);