Image Optimization

Overview

Image optimization is the process of reducing the file size and improving the performance of images on a website, without compromising their visual quality. It involves various techniques such as choosing the right image format, resizing and compressing images, lazy loading, and leveraging responsive images to deliver optimized images that load quickly and efficiently on different devices and network conditions.

How to use

Here we use image optimization. The installation method is as follows below.

The official Next.js image optimization documentation

Step 1: Choose the Right Image Format

Image formats play a crucial role in determining the performance of images on the web. By choosing the right image format, you can reduce the file size of images and improve the loading speed of your web pages. Here's an example of how you can optimize your image format in Next.js:

import Image from 'next/image';

const MyComponent: React.FC = () => {
  return (
    <div>
      <h1>My Image</h1>
      <Image
        src="/images/my-image.jpg"
        alt="My Image"
        width={500}
        height={300}
        layout="responsive"
      />
    </div>
  );
};

export default MyComponent;

Step 2: Use Next.js Image Component

Next.js introduces a new Image component that automatically optimizes images for performance. It provides features like lazy loading, automatic resizing, and format optimization to deliver optimized images for different devices and network conditions. Here's an example of how you can use the Next.js Image component in your Next.js:

import Image from 'next/image';

const MyComponent: React.FC = () => {
  return (
    <div>
      <h1>My Image</h1>
      <Image
        src="/images/my-image.jpg"
        alt="My Image"
        width={500}
        height={300}
        layout="responsive"
      />
    </div>
  );
};

export default MyComponent;

Step 3: Set Image Dimensions

Setting image dimensions is essential for optimizing images in Next.js. By providing accurate width and height attributes to the Image component, you can help the browser allocate the right amount of space for the image, reducing layout shifts and improving performance. Here's an example of how you can set image dimensions in Next.js:

import Image from 'next/image';

const MyComponent: React.FC = () => {
  return (
    <div>
      <h1>My Image</h1>
      <Image
        src="/images/my-image.jpg"
        alt="My Image"
        width={500}
        height={300}
        layout="responsive"
      />
    </div>
  );
};

export default MyComponent;

Step 4: Use Responsive Layout

Responsive layout is crucial for optimizing images for different devices and screen sizes. In Next.js, you can use the layout prop in the Image component to define how the image should be displayed on different devices. Here's an example of how you can use responsive layout in Next.js:

import Image from 'next/image';

const MyComponent: React.FC = () => {
  return (
    <div>
      <h1>My Image</h1>
      <Image
        src="/images/my-image.jpg"
        alt="My Image"
        width={500}
        height={300}
        layout="responsive"
      />
    </div>
  );
};

export default MyComponent;

Step 5: Optimize Image Loading

Optimizing image loading is crucial for improving the performance of your web pages. In Next.js, you can use the placeholder and blurDataURL props in the Image component to show a blurred version of the image while it's loading, reducing the perceived load time. Here's an example of how you can optimize image loading in Next.js:

import Image from 'next/image';

const MyComponent: React.FC = () => {
  return (
    <div>
      <h1>My Image</h1>
      <Image
        src="/images/my-image.jpg"
        alt="My Image"
        width={500}
        height={300}
        layout="responsive"
        placeholder="empty"
        blurDataURL="/images/my-image.jpg"
      />
    </div>
  );
};

export default MyComponent;

In the above example, the placeholder prop is set to "empty", which shows an empty space with the dimensions of the image while it's loading. The blurDataURL prop is set to the data URL of a blurred version of the image, which is displayed as a placeholder until the actual image is loaded. This technique helps to improve the perceived load time of the image, making the web page feel faster to users.

You can also generate the blurred data URL dynamically using third-party libraries or services to further optimize the loading of images in your Next.js application.

By optimizing image loading with techniques like using placeholders and blurred data URLs, you can significantly improve the perceived performance of your web pages, providing a smoother user experience while reducing the actual load time of images.

Step 6: Serve Optimized Images

In addition to optimizing the way images are rendered in the front-end, you can also optimize how images are served from the server in Next.js. You can use Next.js' built-in Image Optimization feature to automatically serve optimized images based on the device's screen size and network conditions, without any extra configuration.

To enable Image Optimization in Next.js, you can add the next/image configuration to your next.config.js file:

module.exports = {
  images: {
    formats: ['image/avif', 'image/webp'],
  },
};

This configuration enables Next.js to serve images in AVIF and WebP formats, which are modern image formats that provide better compression and smaller file sizes compared to older formats like JPEG and PNG. Next.js will automatically convert and serve images in the most suitable format based on the browser's support and the user's device capabilities.

You can also configure other options such as quality, placeholder, and domains in the images configuration object to further optimize the way images are served from the server.

By serving optimized images, you can reduce the bandwidth usage of your web pages, improve the loading speed of images, and provide a better user experience, especially on slow network connections or devices with limited capabilities.