How to create a scroll to top button with JavaScript

Scroll to top buttons allow users to quickly return to the top of a webpage with a single click.

In this tutorial we’ll be creating a button that appears only after scrolling a certain distance down the page.

Let’s start by creating a scrollTop function that will contain all the required JavaScript:

const scrollTop = function () {
// all JavaScript will go here
};
scrollTop();

Next inside the scrollTop function we’ll generate a HTML button element:

const scrollBtn = document.createElement("button");
scrollBtn.innerHTML = "↑";
scrollBtn.setAttribute("id", "scroll-btn");
document.body.appendChild(scrollBtn);

1. Create a const variable named scrollBtn with a HTML button element.
2. Set the text of the button element to ↑ which is an up arrow HTML entity.
3. Give the button an ID of scroll-btn so we can target with CSS.
4. Insert the scrollBtn into the HTML.

Following the previous code add a scrollBtnDisplay function and event listener:

const scrollBtnDisplay = function () {
  window.scrollY > window.innerHeight
    ? scrollBtn.classList.add("show")
    : scrollBtn.classList.remove("show");
};
window.addEventListener("scroll", scrollBtnDisplay);

This toggles a show class when the user has scrolled further down the page than the height of the window.

Finally let’s add the functionality for when a user clicks the button inside the scrollTop function:

const scrollWindow = function () {  
  if (window.scrollY != 0) {
    setTimeout(function () {
      window.scrollTo(0, window.scrollY - 50);
      scrollWindow();
    }, 10);
  }
};
scrollBtn.addEventListener("click", scrollWindow);

Smooth scrolling could be done using CSS scroll-behavior:smooth; but this isn’t yet supported in Safari.

So instead we use a setTimeout that scrolls -50px every 10 milliseconds until the top of the page is reached.

Finally here’s some CSS to create a rounded button that fades in/out when the show class is toggled:

#scroll-btn {       
    opacity: 0;   
    width: 40px;
    height: 40px;
    color: #fff;
    background-color: #ef476f;
    position: fixed;
    bottom: 10%;
    right: 10%;    
    border: 2px solid #fff;
    border-radius: 50%; 
    font: bold 20px monospace;       
    transition: opacity 0.5s, transform 0.5s;
}
#scroll-btn.show {      
    opacity: 1;  
    transition: opacity 1s, transform 1s;     
}

You now have a fully functioning scroll-to-top button to use in you next web project.