16 Mar 2023

Designing a custom dropdown menu with HTML, CSS, and JavaScript

Dropdown menus are a common user interface element that allow users to select an option from a list. While many website builders offer built-in dropdown menus, designing a custom dropdown menu with HTML, CSS, and JavaScript can provide greater control over the appearance and functionality of the menu.

In this blog post, we'll walk through the process of designing a custom dropdown menu with HTML, CSS, and JavaScript. We'll start with the HTML structure, then move on to styling the menu with CSS, and finally add functionality with JavaScript.

HTML Structure

The first step in designing a custom dropdown menu is to create the HTML structure for the menu. We'll create a basic dropdown menu with a single menu item for this example.

<div class="dropdown">
  <button class="dropdown-btn">Menu Item</button>
  <ul class="dropdown-menu">
    <li><a href="#">Option 1</a></li>

In this code, we've created a div element with a class of dropdown. Inside the div, we've added a button element with a class of dropdown-btn that will serve as the dropdown toggle button. We've also added a ul element with a class of dropdown-menu that will contain the dropdown options.

Inside the ul element, we've added a li element with an anchor tag (<a>) that will represent our dropdown option. For this example, we've added a single option with the text "Option 1" and a placeholder link (#) for the href attribute.

Styling with CSS

Now that we have the HTML structure for our dropdown menu, we can style it with CSS. We'll start by hiding the dropdown menu by default and styling the dropdown button.

.dropdown-menu {
  display: none;

.dropdown-btn {
  background-color: #fff;
  border: 1px solid #ccc;
  border-radius: 4px;
  color: #333;
  font-size: 16px;
  padding: 10px 20px;

In this code, we've set the display property of the dropdown-menu class to none to hide the menu by default. We've also styled the dropdown-btn class with a background color, border, border radius, font size, and padding to create a button-like appearance.

Next, we'll add styles to show the dropdown menu when the button is clicked.

.dropdown:hover .dropdown-menu {
  display: block;

.dropdown-menu {
  background-color: #fff;
  border: 1px solid #ccc;
  border-radius: 4px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  margin-top: 5px;
  padding: 0;
  position: absolute;
  z-index: 1;

.dropdown-menu li {
  list-style: none;
  padding: 10px;

.dropdown-menu li:hover {
  background-color: #f2f2f2;

In this code, we've added a hover effect to show the dropdown menu when the user hovers over the dropdown element. We've also added styles to the dropdown-menu class to position it correctly and add a box shadow for a raised appearance.

We've added some additional styles to the li elements inside the dropdown-menu class to remove the bullet points and add padding, and a hover effect to change the background color of the option when the user hovers over it.

Adding Functionality with JavaScript

Now that we've created the HTML and styled the dropdown menu with CSS, we can add functionality with JavaScript. Specifically, we'll add an event listener to the dropdown button that will toggle the display of the dropdown menu.

const dropdownBtn = document.querySelector('.dropdown-btn');
const dropdownMenu = document.querySelector('.dropdown-menu');

dropdownBtn.addEventListener('click', function() {

In this code, we've used document.querySelector() to select the dropdown-btn and dropdown-menu elements and assigned them to variables dropdownBtn and dropdownMenu.

We've then added an event listener to the dropdownBtn element that listens for a click event. When the button is clicked, the function passed to the event listener toggles the show class on the dropdownMenu element using classList.toggle(). This will show or hide the dropdown menu, depending on its current state.

And there you have it! By combining HTML, CSS, and JavaScript, we've designed a custom dropdown menu that can be easily customized and integrated into a website. With some additional CSS and JavaScript, you can add additional features like animations, dropdown arrows, or keyboard navigation to further enhance the user experience.