svelte-imgix

Svelt Imgix

Svelte action for generating responsive, lazily-loaded images with Imgix

Features

• Generate responsive image srcsets automatically
• Optional lazy loading with automatic LQIP placeholders

Basic Usage

npm i svelte-imgix

<script>
  import imgix from 'svelte-imgix';
</script>

<img use:imgix="https://assets.imgix.net/unsplash/vintagecameras.jpg" />

With config

Rather than passing a src image to use:imgix, you can pass a full configuration object with the following properties

Property	Default	Description
src	''	Src of the image
lazyload	false	Delay loading the full res image until it's in view
imgixProps	{}	Additional imgix properties to pass to the image

<img use:imgix={{
  src: 'https://assets.imgix.net/unsplash/vintagecameras.jpg',
  lazyload: false,
  imgixParams: {
    fit: 'crop',
    ar:  '16:9'
  }
}} />

Helper functions

Svelte Imgix exports 2 additional helpers that you can use to create responsive source sets and LQIP placeholders yourself, srcset(src) and placeholder(src);

<script>
  import { placeholder, srcset } from 'svelte-imgix';
  import { invew } from 'svelte-inview';

  let src = '';
  let intersected = false;
</script>

<img src={intersected ? src : placeholder(src)} srcset={intersected ? srcset(src} : ''} use:invew on:enter={() => intersected = true} />

SSR Support

Until Svelte supports actions running in SSR, you might notice images don't have a src at all until svelte-imgix has hydrated. As a workaround, use the placeholder helper function to SSR an LQIP placeholder image manually. Svelte-imgix will then hydrate from there, with the same placeholder image, and load your full srcset once the image enters the viewport.

<img use:imgix={src} src={placeholder(src)} />

Adding Sizes

Svelte-Imgix automatically generates a responsive srcset for a huge range of viewport sizes. By adding a sizes attribute to your image you can instruct the browser to use the appropriate source based on media queries.

See the MDN article on responsive images for a thorough walkthrough.