How can you optimize image loading in Next.js?

While developing my web application with Next.js, I noticed that images are contributing significantly to the page load time, especially for users on slower networks. I want to ensure that the user experience remains smooth and responsive without compromising image quality.

I’ve read that Next.js provides some built-in image optimization capabilities, but I’m not exactly sure how to implement them properly. I’ve used regular <img> tags so far, but they don’t seem to offer any performance benefits.

I’m looking for a reliable way to optimize images in my Next.js project - ideally through native features - to improve load times, handle responsiveness, and reduce bandwidth usage. How should I approach this?

Use the `Image` Component from `next/image`

Instead of using a regular <img> tag, import and use the Image component:

1import Image from 'next/image';
2export default function Profile() {
3  return (
4    <Image
5      src="/images/profile.jpg" // Can also be a remote URL
6      alt="Profile photo"
7      width={300}
8      height={300}
9    />
10  );
11}

1import Image from 'next/image';
2export default function Profile() {
3  return (
4    <Image
5      src="/images/profile.jpg" // Can also be a remote URL
6      alt="Profile photo"
7      width={300}
8      height={300}
9    />
10  );
11}

Benefits of `next/image`:

Automatic lazy loading: Images load only when they enter the viewport.
Responsive loading: Next.js serves appropriately sized images based on device size and resolution.
Optimized formats: Images are served in modern formats like WebP when supported.
Blur-up placeholders: Adds a nice blur effect while the image loads.

Additional Optimization Features:

1. Responsive Layouts

You can make the image responsive by using the layout="responsive" prop (for older versions) or using the fill prop in newer versions with Tailwind or custom styles.

1<Image
2  src="/images/banner.jpg"
3  alt="Banner"
4  width={1200}
5  height={600}
6  style={{ width: '100%', height: 'auto' }}
7/>

1<Image
2  src="/images/banner.jpg"
3  alt="Banner"
4  width={1200}
5  height={600}
6  style={{ width: '100%', height: 'auto' }}
7/>

2. Remote Images (External URLs)

Add the domain to your next.config.js file:

1module.exports = {
2  images: {
3    domains: ['example.com'],
4  },
5};

1module.exports = {
2  images: {
3    domains: ['example.com'],
4  },
5};

3. Use Placeholder Blur (Progressive Loading)

1<Image
2  src="/images/photo.jpg"
3  alt="Photo"
4  width={500}
5  height={500}
6  placeholder="blur"
7  blurDataURL="/images/placeholder.jpg"
8/>

1<Image
2  src="/images/photo.jpg"
3  alt="Photo"
4  width={500}
5  height={500}
6  placeholder="blur"
7  blurDataURL="/images/placeholder.jpg"
8/>