aknow2

const element = document.createElement('div'); document.body.appendChild(element) ; element.style.position='fixed'; element.style.right='0'; element.style.top='0'; element.style.zIndex='999'; let prev = 0; const fps = (current) => { (current-prev) && (element.innerText = Math.floor(1000/(current - prev)).toString()); prev = current; requestAnimationFrame(fps)  }; requestAnimationFrame(fps);