Github Repo: https://github.com/PSkinnerTech/qrcode-vanilla/
Demo: https://qrcode-vanilla.netlify.app/
In this tutorial, we will create a static QR Code Generator application using vanilla JavaScript, HTML, and Tailwind CSS. The application will allow users to enter a URL, generate a QR code, and download the QR code as an image.
Prerequisites
Before starting this tutorial, you should have a basic understanding of:
Setting up the project
Create a new folder called qr-code-generator.
Inside the qr-code-generator folder, create the following files and folders:
codeqr-code-generator/
|-- img/
| |-- qrcode.svg
|-- js/
| |-- script.js
|-- index.html
Creating the HTML structure
Open the index.html file and add the following code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta
name="description"
content="Generate a QR code image to point to a website URL"
/>
<meta
name="keywords"
content="qr code, qr codes, qrcodes, create qr code, qr code generator, create qrcodes, make a qr code, online qr code"
/>
<link rel="shortcut icon" type="image/x-icon" href="/favicon.ico" />
<link rel="preconnect" href="https://fonts.googleapis.com" />
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
<link
href="https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;700&display=swap"
rel="stylesheet"
/>
<script src="https://cdn.tailwindcss.com"></script>
<script>
tailwind.config = {
theme: {
extend: {
fontFamily: {
sans: ["Poppins", "sans-serif"],
},
},
},
};
</script>
<script
src="https://cdnjs.cloudflare.com/ajax/libs/qrcodejs/1.0.0/qrcode.min.js"
integrity="sha512-CNgIRecGo7nphbeZ04Sc13ka07paqdeTu0WR1IM4kNcpmBAUSHSQX0FslNhTDadL4O5SAGapGt4FodqL8My0mA=="
crossorigin="anonymous"
referrerpolicy="no-referrer"
></script>
<script src="js/script.js" defer></script>
<style>
#spinner {
display: none;
}
</style>
<title>Free Online QR Code Generator</title>
</head>
<body>
<header class="p-4 mb-10 bg-green-500">
<div class="max-w-5xl m-auto">
<div class="text-xl font-bold text-white">QR Code Generator</div>
</div>
</header>
<img src="img/spinner.svg" alt="" />
<main>
<div
class="flex flex-col-reverse align-center justify-center m-auto md:max-w-4xl p-10 md:flex-row"
>
<div class="w-full md:w-2/3 mr-24">
<h1 class="text-3xl font-bold mb-5 md:text-4xl">QR Code Generator</h1>
<p class="mb-4">
QR Codes allow smartphone users to access your website simply and
quickly.
</p>
<p>
Enter your URL below to generate a QR Code and download the image.
</p>
<form id="generate-form" class="mt-4">
<input
id="url"
type="url"
placeholder="Enter a URL"
class="w-full border-2 border-gray-200 rounded p-3 text-grey-dark mr-2 focus:outline-none mb-5"
required
/>
<select
class="w-full border-2 border-gray-200 rounded p-3 text-grey-dark mr-2 focus:outline-none"
name="size"
id="size"
>
<option value="100">100x100</option>
<option value="200">200x200</option>
<option value="300" selected>300x300</option>
<option value="400">400x400</option>
<option value="500">500x500</option>
<option value="600">600x600</option>
<option value="700">700x700</option>
</select>
<button
class="bg-gray-600 rounded w-full text-white py-3 px-4 mt-5 hover:bg-black"
type="submit"
>
Generate QR Code
</button>
</form>
</div>
<div class="w-full md:w-1/3 self-center">
<img
class="w-1/2 m-auto mb-10 md:w-full"
src="img/qrcode.svg"
alt=""
/>
</div>
</div>
<div
id="generated"
class="max-w-5xl m-auto flex flex-col text-center align-center justify-center mt-20"
>
<div id="spinner" role="status">
<svg
class="inline mr-2 w-24 h-24 text-gray-200 animate-spin dark:text-gray-600 fill-pink-600"
viewBox="0 0 100 101"
fill="none"
xmlns="http://www.w3.org/2000/svg"
>
<path
d="M100 50.5908C100 78.2051 77.6142 100.591 50 100.591C22.3858 100.591 0 78.2051 0 50.5908C0 22.9766 22.3858 0.59082 50 0.59082C77.6142 0.59082 100 22.9766 100 50.5908ZM9.08144 50.5908C9.08144 73.1895 27.4013 91.5094 50 91.5094C72.5987 91.5094 90.9186 73.1895 90.9186 50.5908C90.9186 27.9921 72.5987 9.67226 50 9.67226C27.4013 9.67226 9.08144 27.9921 9.08144 50.5908Z"
fill="currentColor"
/>
<path
d="M93.9676 39.0409C96.393 38.4038 97.8624 35.9116 97.0079 33.5539C95.2932 28.8227 92.871 24.3692 89.8167 20.348C85.8452 15.1192 80.8826 10.7238 75.2124 7.41289C69.5422 4.10194 63.2754 1.94025 56.7698 1.05124C51.7666 0.367541 46.6976 0.446843 41.7345 1.27873C39.2613 1.69328 37.813 4.19778 38.4501 6.62326C39.0873 9.04874 41.5694 10.4717 44.0505 10.1071C47.8511 9.54855 51.7191 9.52689 55.5402 10.0491C60.8642 10.7766 65.9928 12.5457 70.6331 15.2552C75.2735 17.9648 79.3347 21.5619 82.5849 25.841C84.9175 28.9121 86.7997 32.2913 88.1811 35.8758C89.083 38.2158 91.5421 39.6781 93.9676 39.0409Z"
fill="currentFill"
/>
</svg>
<span class="sr-only">Loading...</span>
</div>
<div id="qrcode" class="m-auto"></div>
</div>
</main>
</body>
</html>
Styling the application with Tailwind CSS
We have already included the Tailwind CSS CDN in the <head> section of our HTML file. We have also added a custom font, Poppins, from Google Fonts. The application should now be styled with Tailwind CSS.
Adding interactivity with JavaScript
We have already added the script tag for qrcode.js library and included our custom script.js file with the defer attribute in the <head> section. Open the script.js file and add the following code:
const form = document.getElementById("generate-form");
const qr = document.getElementById("qrcode");
const onGenerateSubmit = (e) => {
e.preventDefault();
clearUI();
const url = document.getElementById("url").value;
const size = document.getElementById("size").value;
if (url === "") {
alert("Please enter a URL");
} else {
showSpinner();
setTimeout(() => {
hideSpinner();
generateQRCode(url, size);
setTimeout(() => {
const saveUrl = qr.querySelector("img").src;
createSaveBtn(saveUrl);
}, 50);
}, 1000);
}
};
const generateQRCode = (url, size) => {
const qrcode = new QRCode("qrcode", {
text: url,
width: size,
height: size,
});
};
const clearUI = () => {
qr.innerHTML = "";
const saveBtn = document.getElementById("save-link");
if (saveBtn) {
saveBtn.remove();
}
};
const showSpinner = () => {
const spinner = document.getElementById("spinner");
spinner.style.display = "block";
};
const hideSpinner = () => {
const spinner = document.getElementById("spinner");
spinner.style.display = "none";
};
const createSaveBtn = (saveUrl) => {
const link = document.createElement("a");
link.id = "save-link";
link.className =
"bg-green-500 hover:bg-black text-white font-bold py-2 rounded w-1/3 m-auto my-5";
link.href = saveUrl;
link.download = "qrcode";
link.innerHTML = "Save Image";
document.getElementById("generated").appendChild(link);
};
hideSpinner();
form.addEventListener("submit", onGenerateSubmit);
This code handles the following functionality:
Conclusion
In this tutorial, we have built a static QR Code Generator using vanilla JavaScript, HTML, and Tailwind CSS. We have implemented form submission, QR code generation, and the ability to download the QR code as an image. This application provides a simple and efficient way for users to generate QR codes for URLs.
You can now use this QR Code Generator to create QR codes for your website or any other URLs you want to share quickly and easily. The application is easy to customize and extend, so feel free to make any adjustments or add new features to suit your needs.
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Happy Building! (🧱 , 🚀 )
