//Get the button let mybutton = document.getElementById("btn-back-to-top"); // When the user scrolls down 20px from the top of the document, show the button window.onscroll = function () { scrollFunction(); }; function scrollFunction() { if ( document.body.scrollTop > 20 || document.documentElement.scrollTop > 20 ) { mybutton.style.display = "block"; } else { mybutton.style.display = "none"; } } // When the user clicks on the button, scroll to the top of the document mybutton.addEventListener("click", backToTop); function backToTop() { document.body.scrollTop = 0; document.documentElement.scrollTop = 0; }