@unlazy/svelte

unlazy is not only framework-agnostic, but also provides a Svelte component that you can use in your Svelte application.

INFO

The component is written for Svelte 5 and above using runes.

Installation

Install the @unlazy/svelte package using your favorite package manager:

pnpm

pnpm add -D @unlazy/svelte

yarn

yarn add -D @unlazy/svelte

npm

npm install -D @unlazy/svelte

Import the UnLazyImage component in your component file:

<script lang="ts">
  import { UnLazyImage } from '@unlazy/svelte'
</script>

<UnLazyImage
  blurhash="LKO2:N%2Tw=w]~RBVZRi};RPxuwH"
  srcSet="image-320w.jpg 320w, image-640w.jpg 640w"
  autoSizes
/>

UnLazyImage Component

The UnLazyImage component allows you to easily implement unlazy in your Svelte application, providing a smoother image loading experience.

The component supports automatic calculation of the sizes attribute with the autoSizes prop. It also enables you to specify a blurhash for the blurry placeholder image.

Props

The UnLazyImage component accepts the following props:

Prop	Type	Description
src	String	Image source URL to be lazy-loaded.
srcSet	String	Image source set to be lazy-loaded.
autoSizes	Boolean	A flag to indicate whether the sizes attribute should be automatically calculated.
blurhash	String	A BlurHash string representing the blurry placeholder image.
thumbhash	String	A ThumbHash string representing the blurry placeholder image.
placeholderSrc	String	Optional image source URL for a custom placeholder image. Will be ignored if a BlurHash or ThumbHash is provided.
placeholderSize	Number	The size of the longer edge (width or height) of the BlurHash image to be decoded, depending on the aspect ratio. This option only applies when the blurhash prop is used.

Examples

BlurHash

<UnLazyImage
  blurhash="LKO2:N%2Tw=w]~RBVZRi};RPxuwH"
  srcSet="image-320w.jpg 320w, image-640w.jpg 640w"
  autoSizes
/>

ThumbHash

<UnLazyImage
  thumbhash="1QcSHQRnh493V4dIh4eXh1h4kJUI"
  srcSet="image-320w.jpg 320w, image-640w.jpg 640w"
  autoSizes
/>

Inlined placeholder image

<UnLazyImage
  placeholderSrc="data:image/svg+xml, ..."
  srcSet="image-320w.jpg 320w, image-640w.jpg 640w"
  autoSizes
/>

TIP

In each example, the sizes attribute is automatically calculated given the auto-sizes prop.