Create a Dark/Light Mode Switch using HTML CSS & JavaScript in 10 Minutes!

U-GINE MEDIA November 25, 2025

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In this tutorial topic "Create a Dark/Light Mode Switch using HTML CSS & JavaScript in 10 Minutes!", we will learn how to create it following these simple easy steps.

Share this to your programmer friends. If y'all learnt something today, make sure to let me in the comments. 

Get Source Code.

If interested in watching the video before running the code below, you can click the play button to get started.



Code Begins

  1. First, create a folder with any name you like. Then, make the necessary files inside it.
  2. Create a file called index.html to serve as the main file.
  3. Create a file called style.css for the CSS code.
  4. Create a file called script.js for the JavaScript code.

To start, add the following HTML codes to your index.html file. These codes include essential HTML markup with different semantic tags, such as div, form, input, button, image, etc., to build the website layout. 

HTML


<!DOCTYPE html>
<html lang="en">
  <head>
    <link rel="stylesheet" href="style.css" />
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Toggle Dark/Light Mode</title>
  </head>
  <body>
    <input type="checkbox" id="darkmode-toggle" />
    <label for="darkmode-toggle">
      <img src="./sun.png" class="sun" alt="" />
      <img
        src="./moon.png"
        class="moon"
        alt=""
        style="filter: grayscale(100%)"
      />
    </label>

    <div class="background"></div>

    <script src="script.js"></script>
  </body>
</html>

Next, add the following CSS codes to your style.css file to make website beautiful and user-friendly. You can customize the different CSS properties, such as color, background, font, etc., to give a personalized touch to your website. 

CSS


      body {
        margin: 0;
        width: 100vw;
        height: 100vh;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
      }

      label {
        width: 500px;
        height: 200px;
        position: relative;
        display: block;
        background: #ebebeb;
        border-radius: 200px;
        box-shadow: inset 0px 5px 15px rgba(0, 0, 0, 0.4),
          inset 0px -5px 15px rgba(255, 255, 255, 0.4);
        cursor: pointer;
        transition: 0.3s;
        &:after {
          content: "";
          width: 180px;
          height: 180px;
          position: absolute;
          top: 10px;
          left: 10px;
          background: linear-gradient(180deg, #ffcc89, #d8860b);
          border-radius: 180px;
          box-shadow: 0px 5px 10px rgba(0, 0, 0, 0.2);
          transition: 0.3s;
        }
        img {
          position: absolute;
          width: 120px;
          top: 40px;
          z-index: 100;
          &.sun {
            left: 40px;
            filter: invert(100%);
            transition: 0.3s;
          }
          &.moon {
            left: 340px;
            filter: grayscale(100%);
            opacity: 0.7;
            transition: 0.3s;
          }
        }
      }

      input {
        width: 0;
        height: 0;
        visibility: hidden;
        &:checked + label {
          background: #242424;
          &:after {
            left: 490px;
            transform: translateX(-100%);
            background: linear-gradient(180deg, #777, #3a3a3a);
          }
          + .background {
            background: #242424;
          }
        }
        &:active:after {
          width: 260px;
        }
      }

      .background {
        width: 100vw;
        height: 100vh;
        background: #fff;
        z-index: -1;
        position: absolute;
        transition: 0.3s;
      }

Finally, add the following JavaScript code to your script.js file to make your work functional. This code handles various functions, even listeners, input handling, etc.

JAVASCRIPT


const darkModeToggle = document.getElementById("darkmode-toggle");
let background = document.querySelector(".background");
let label = document.querySelector("label");

darkModeToggle.addEventListener("change", (e) => {
  if (e.currentTarget.checked) {
    localStorage.setItem("theme", "dark");
    background.style.background = "#242424";
    label.style.background = "#242424";
  } else {
    localStorage.setItem("theme", "light");
    background.style.background = "#fff";
    label.style.background = "#fff";
  }
});

window.addEventListener("DOMContentLoaded", (_) => {
  let theme = localStorage.getItem("theme");
  if (theme === "dark") {
    darkModeToggle.checked = true;
    background.style.background = "#242424";
    label.style.background = "#242424";
  } else {
    darkModeToggle.checked = false;
    background.style.background = "#fff";
    label.style.background = "#fff";
  }
});

Conclusion and Final word

Now, we have reached the end of our code, for any information, you can comment any problem or code-not-working issues to resolve it, am always with you. You can also visit my YouTube Channel for more updates on HTML, CSS & JavaScript Designs. I believe you can create "a Dark/Light Mode Switch using HTML CSS & JavaScript in 10 Minutes!". and do so much more with codes. Go extremely far in exploring the world of HTML, CSS & JavaScript, its gonna be fun, trust me 😃.

Happy Coding Journey 🚀
U-GINE MEDIA

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