<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Image‑Preview Feature Demo</title>
<!-- 1️⃣ CSS – include it in <head> (or link an external file) -->
  <style>
    /* --- CSS START --- */
    /* Basic reset for the demo */
    *, *::before, *::after  box-sizing: border-box; margin:0; padding:0;
body 
      font-family: system-ui, sans-serif;
      background: #f5f5f5;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 100vh;
/* Container for the thumbnail */
    .img-preview 
      position: relative;
      max-width: 90vw;               /* keep it inside the viewport */
      max-height: 80vh;
      cursor: zoom-in;
      overflow: hidden;
      border-radius: 8px;
      box-shadow: 0 4px 12px rgba(0,0,0,.15);
.img-preview img 
      width: 100%;
      height: auto;
      display: block;
      transition: transform .3s ease;
.img-preview:hover img 
      transform: scale(1.02);
/* Light‑box overlay */
    .lightbox 
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,.85);
      display: none;                     /* hidden by default */
      justify-content: center;
      align-items: center;
      z-index: 9999;
      opacity: 0;
      transition: opacity .3s ease;
.lightbox.open 
      display: flex;
      opacity: 1;
.lightbox img 
      max-width: 95vw;
      max-height: 95vh;
      border-radius: 8px;
      animation: zoomIn .3s ease forwards;
@keyframes zoomIn 
      from  transform: scale(.8); opacity:0; 
      to    transform: scale(1);   opacity:1;
.lightbox .close 
      position: absolute;
      top: 1.2rem;
      right: 1.2rem;
      font-size: 2rem;
      color: #fff;
      cursor: pointer;
      background: transparent;
      border: none;
/* Simple placeholder when image fails */
    .img-preview .placeholder 
      display: flex;
      align-items: center;
      justify-content: center;
      background: #e0e0e0;
      color: #555;
      font-size: 1rem;
      width: 100%;
      height: 100%;
/* --- CSS END --- */
  </style>
</head>
<body>
<!-- 2️⃣ MARKUP -->
  <div class="img-preview" tabindex="0">
    <!-- Lazy‑load attribute is supported by all modern browsers -->
    <img src="https://www.zupimages.net/up/23/07/n9top"
         loading="lazy"
         alt="Demo image – replace with your own"
         onerror="this.style.display='none'; this.parentNode.appendChild(document.createElement('div')).className='placeholder'; this.parentNode.lastChild.textContent='Image unavailable';">
<!-- Optional caption -->
    <figcaption style="position:absolute;bottom:0;left:0;right:0;background:rgba(0,0,0,.5);color:#fff;padding:.4rem;text-align:center;font-size:.9rem;">
      Click to enlarge
    </figcaption>
  </div>
<!-- Light‑box container (hidden until opened) -->
  <div class="lightbox" id="lb">
    <button class="close" aria-label="Close lightbox">×</button>
    <img src="https://www.zupimages.net/up/23/07/n9top"
         alt="Full‑size preview">
  </div>
<!-- 3️⃣ JavaScript – make it interactive -->
  <script>
    // --- JS START ---
    (function () 
      const preview   = document.querySelector('.img-preview');
      const lightbox  = document.getElementById('lb');
      const lbImg     = lightbox.querySelector('img');
      const closeBtn  = lightbox.querySelector('.close');
// Open the lightbox
      function openLightbox() 
        lightbox.classList.add('open');
        // Prevent background scroll while the overlay is open
        document.body.style.overflow = 'hidden';
// Close the lightbox
      function closeLightbox() 
        lightbox.classList.remove('open');
        document.body.style.overflow = '';
// Click on thumbnail → open
      preview.addEventListener('click', openLightbox);
// Keyboard: ENTER on the focused thumbnail opens it
      preview.addEventListener('keydown', e =>  e.key === ' ') openLightbox();
      );
// Click on × or outside the image → close
      closeBtn.addEventListener('click', closeLightbox);
      lightbox.addEventListener('click', e => 
        if (e.target === lightbox) closeLightbox();
      );
// ESC key closes the overlay
      document.addEventListener('keydown', e => 
        if (e.key === 'Escape' && lightbox.classList.contains('open')) 
          closeLightbox();
);
    )();
    // --- JS END ---
  </script>
</body>
</html>

If your real goal is to write an article about using img src with ZupImages, here is a long-form, SEO-friendly article based on that theme.


The img src attribute defines the path to the image you want to display on a web page. It can be:

Without a valid src, no image appears — only an empty box or an alt text.


ZupImages is a free, no-registration-required image hosting service launched in 2016. It allows users to upload images and receive direct links, BBCodes, and HTML codes for forums, blogs, or websites. Key features:


If you need to change the image source dynamically:

document.getElementById("myImage").src = "https://www.zupimages.net/up/23/07/n9top.jpg";

Or build the URL based on variables:

let year = "23";
let month = "07";
let code = "n9top";
let imgSrc = `https://www.zupimages.net/up/$year/$month/$code.jpg`;