Images are an important part of any website or application. They help to make the content more engaging and visually appealing.

However, if images are not properly optimized, they can also slow down a site or app.

Why Optimize Images?

There are a few reasons why it’s important to optimize images.

  • It can help to improve the load time of the site or application.
  • It can reduce the amount of data that a client needs to download, which can save on bandwidth costs.
  • It can help to improve the overall performance of the site or application.

How to Optimize Images in Next.js

There are several ways you can optimize images in Next.js. One is to use the Image component. This component automatically optimizes images for performance.

Another way to optimize images is to use built-in image processing capabilities. Next.js can automatically resize, compress, and optimize images for performance.

Finally, you can use a third-party library like react-optimized-image. This library provides a variety of image optimization capabilities.

Using the Image Component

The Image component is the easiest way to optimize images in Next.js. To use it, simply import the component from the next/image package.

Once you’ve imported the component, you can use it like any other in React. The Image component has a few props that you can use to control how it renders images. 

        import Image from 'next/image'

export default function MyImage() {
  return (
    <Image
      src="/my-image.jpg"
      width="200"
      height="200"
      quality="100"
      alt="My image"
    />
  )
}

In this example, the Image component renders an image with a width of 200px and a height of 200px. You can also use CSS or a framework like Tailwind to style your app and images.

Some of the required props for the Image component are width, height, src, and alt. The src prop is the URL of the image that you want to use. Use the width and height props to set the width and height of the image, in pixels. The alt prop is the alternate text for the image.

Some optional props for the Image component are layout, loader, placeholder, and priority. The layout prop specifies the layout of the image. You can use the loader prop to specify a custom image loader. The placeholder prop specifies a custom image placeholder. The priority prop specifies the priority of the image.

Some of the benefits of using the Image component are:

  • Improved Performance: One of the main benefits of using the Image component is improved performance. The component automatically optimizes images for performance.
  • Automatic Image Resizing: Another benefit of using the Image component is automatic image resizing. The component can automatically resize images to fit the width and height props.
  • Automatic Image Compression: The Image component can also automatically compress images to reduce file size.
  • Lazy Loading Support: The Image component also supports lazy loading. This means that it will only load images when they are visible on the screen.

Using a Third-Party Library

If you need more control over image optimization, you can use a third-party library like react-optimized-image. This library provides a variety of image optimization capabilities.

Some of the features of react-optimized-image include:

  • Optimize images on the client and server: react-optimized-image can optimize images on the client and server. This means that images are optimized for performance as well as file size.
  • Automatic image resizing: react-optimized-image can automatically resize images to fit the width and height props.
  • Automatic image compression: react-optimized-image can also automatically compress images to reduce file size.
  • Lazy loading support: react-optimized-image also supports lazy loading. This means that it will only load images when they are visible on the screen.
  • Support for multiple image formats: react-optimized-image supports multiple image formats, including JPEG, PNG, and WebP.

To use react-optimized-image, simply install the library with npm.

Once you’ve installed the library, you can import it into your project. 

        import Img from 'react-optimized-image'

export default function NextImg() {
  return (
    <Img
      src="/my-image.jpg"
      sizes={[400, 800]}
      alt="My image"
    />
  )
}

You can also use SVG files with react-optimized-image. 

        import {Svg} from 'react-optimized-image'

export default function NextImg() {
  return (
    <Svg
      src="/my-image.svg"
      className=&ldquo;filled-red&rdquo;
    />
  )
}

This example uses the className prop to specify a class name for the SVG. You can use that class name to style the SVG with CSS or interact with it using JavaScript.

react-optimized-image also provides a few other benefits over the built-in image optimization capabilities.

One benefit of using a package over built-in features is that it can automatically generate different sizes of images. This means that you don’t have to create different versions of the same image.

Another benefit is that it can automatically serve the appropriate size of image for the user’s device. This means that devices with high-resolution screens will get a high-resolution image, and devices with low-resolution screens will get a low-resolution image.

Finally, react-optimized-image is a completely open-source project. This means that you can contribute to the library if you need a specific feature or bug fix.

Which Method Should You Use?

So, which method should you use to optimize images in Next.js?

If you need basic image optimization, then you can use the built-in image processing capabilities. This is the easiest way to get started with image optimization.

If you need more control over image optimization, then you can use a third-party library like react-optimized-image. This library provides more advanced image optimization capabilities.

If you need the absolute best performance, then you can use a combination of the built-in image processing capabilities and a third-party library. This will give you the best of both worlds. However, this approach is not recommended for beginners since it requires more setup.

Improve SEO With Optimized Images

By optimizing the images on your website or app, you can improve your SEO. Google’s algorithm takes into account the loading speed of websites and apps. If your website or app loads slowly, it will negatively impact your SEO.

With optimized images, you can improve the load time of your website or app, which can improve your SEO. After that, you can also add open graph protocol for even better performance.