Boosting Next.js App Performance with BlurHash Image Placeholders

The Problem with Large Images

Images can significantly impact page speed and user experience. The larger the image, the longer it takes to load, which can lead to a slower overall page load time. This can be especially problematic for users with slower internet connections.

What are Image Placeholders?

Image placeholders are dummy images that are loaded initially to represent the actual image until it has been downloaded. They can enhance page speed by reducing the number of image files on initial load.

Introducing BlurHash

BlurHash is a method for generating blurred versions of images. The resulting string of characters can be used as a placeholder for the image, providing a more visually appealing alternative to traditional image placeholders.

How BlurHash Works

The BlurHash algorithm analyzes an image and generates a string that serves as the image’s placeholder. This process is typically done on the backend, where the image URL is stored. The BlurHash string and image URL are then sent to the client together.

The Impact of BlurHash on Page Speed

Using BlurHash image placeholders can significantly improve page speed. By reducing the amount of data that needs to be transferred, BlurHash can help ensure that pages load quickly, even on slower internet connections.

Implementing BlurHash in Next.js

Implementing BlurHash in Next.js is relatively straightforward. For static images, you can generate BlurHash placeholders using the placeholder attribute on the Image component. For dynamic images, you’ll need to use the blurDataUrl attribute.

Generating BlurHash Placeholders for Static Images

To generate BlurHash placeholders for static images, you can use the following code:

import Image from 'next/image';

const MyImage = () => {
  return (
    <Image
      src="image.jpg"
      placeholder="blur"
      blurDataURL="data:image/jpeg;base64,..."
    />
  );
};

Generating BlurHash Placeholders for Dynamic Images

To generate BlurHash placeholders for dynamic images, you’ll need to use the blurDataUrl attribute. You can use a library like plaiceholder to generate the BlurHash placeholder.

import Image from 'next/image';
import { plaiceholder } from 'plaiceholder';

const MyDynamicImage = ({ src }) => {
  const blurhash = plaiceholder(src);

  return (
    <Image
      src={src}
      placeholder="blur"
      blurDataURL={blurhash}
    />
  );
};

By implementing BlurHash image placeholders, you can significantly improve the performance of your Next.js app. Whether you’re working with static or dynamic images, using BlurHash is a simple and effective way to boost your app’s performance.