🖼️ Image Optimization in Next.js v15 – Why You Should Use next/image

You’ve added a logo to your header — awesome!

But if you’re still using the basic HTML <img> tag, you’re missing out on one of the most powerful features of Next.js:

The built-in Image component from next/image, which automatically optimizes images for performance, responsiveness, and speed 🚀

Let’s learn why you should switch and how to do it — step by step 👇

---

🔍 The Problem with <img>

Sure, the standard <img> works. But it doesn’t:

• Lazy-load by default

• Resize or optimize the image automatically

• Choose the best format for each browser

• Prevent layout shifts (that flicker you sometimes see)

In modern web development, images are one of the biggest performance bottlenecks — and Next.js helps fix that.

---

✅ The Solution: Use next/image

Next.js includes a built-in Image component that:

✅ Lazy loads images automatically
✅ Chooses the best format (like WebP) based on browser
✅ Handles image resizing and responsiveness
✅ Prevents layout shifts with defined dimensions
✅ Can be prioritized when needed (e.g. for logos or above-the-fold images)

---

🧠 Let’s Upgrade Your Logo

Let’s say you previously used:

<img src={logo.src} alt="A plate with food" />

To upgrade it:

Step 1: Import the Component

import Image from 'next/image';

Step 2: Use the <Image> component

<Image
  src={logo}            // Not logo.src – pass the whole imported object
  alt="A plate with food"
  width={50}
  height={50}
  priority               // Make it load early (optional but recommended for logos)
/>

✅ That's it! The image will now:

• Load faster

• Avoid flickering

• Adjust to the user’s screen

• Be served in modern formats like WebP (in Chrome)

---

📁 What Happens Behind the Scenes?

When you import an image like:

import logo from '@/assets/logo.png';

Next.js doesn’t just give you a string. It returns an object with:

• src – the actual path

• height & width – dimensions (if detectable)

• blurDataURL – for placeholder blur (optional)

By passing the entire object into <Image />, you allow Next.js to handle:

• Automatic sizing

• Format conversion

• Responsive behavior

• Lazy loading (unless overridden with priority)

---

⚠️ Common Mistakes to Avoid

---

🧪 Pro Tip: Use the Browser DevTools to Inspect the Output

• In the Elements tab, you’ll see a real <img> tag generated from the <Image> component

• In the Network tab, you’ll see images loaded in formats like WebP instead of PNG

• This shows how smartly Next.js adapts to modern browsers

---

📌 Final Thoughts

Switching to <Image /> is a one-line upgrade with big performance benefits. In a real-world app, this can dramatically improve page speed and SEO.