A tiny script and component intended to be used with Astro for generating images with eleventy-img. It also supports creating blurry placeholders for said images
It was mostly made for my own website and I do not intend to really support this outside of my own needs as more modern and generalist solutions are in the work for Astro
npm install astro-eleventy-img
Due to an issue in the current version of Vite used by Astro, you need to add the following to your astro project config file:
vite: {
ssr: {
external: ["@11ty/eleventy-img"],
},
},
The best way to use this in my opinion is to use it to generate images in the public
folder. That way, they're copied directly to the result website. This is the default behavior.
---
import { generateImage } from 'astro-eleventy-img';
const myImage = generateImage('src/assets/my_image.png', {
// The options here are passed directly to eleventy-img
widths: [300],
formats: ['webp', 'avif'],
});
---
<img src={myImage.webp[0].url} />
generateImage
returns an object containing all the formats generated and metadata you can use in your HTML, so myImage is equal to:
{
webp: [
{
format: 'webp',
width: 300,
height: 240,
url: '/assets/images/RfSNa8TCUW-300.webp',
sourceType: 'image/webp',
srcset: '/assets/images/RfSNa8TCUW-300.webp 300w',
filename: 'RfSNa8TCUW-300.webp',
outputPath: 'public/assets/images/RfSNa8TCUW-300.webp'
}
],
avif: [
{
format: 'avif',
width: 300,
height: 240,
url: '/assets/images/RfSNa8TCUW-300.avif',
sourceType: 'image/avif',
srcset: '/assets/images/RfSNa8TCUW-300.avif 300w',
filename: 'RfSNa8TCUW-300.avif',
outputPath: 'public/assets/images/RfSNa8TCUW-300.avif'
}
]
}
The following files will be generated in the public/assets/images
folder:
RfSNa8TCUW-300.webp
RfSNa8TCUW-300.avif
---
import { generatePlaceholder } from 'astro-eleventy-img';
const myPlaceholder = generatePlaceholder('src/assets/my_image.png');
---
<img src={myPlaceholder.dataURI} width={myPlaceholder.width} height={myPlaceholder.height} />
generatePlaceholder
return an object containing all the properties needed for showing the image. So myPlaceholder
in this example is equal to:
{
dataURI: 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAkAAAAHCAIAAABV+fA3AAAACXBIWXMAAAsTAAALEwEAmpwYAAAAz0lEQVQImQHEADv/AJ7Ho7PYwTt5UhdkNjmLSUOPUCB4MSFzMkGMNACixqksb04WUy4wdz9cnFxPnksbaS0HTCo3hDUAnLmcRnFLQ289ZpZXn7Z9MpA+OYU9EFstVZpHAJ3GaqnPbJXFW5iyZNzLqZWvco+9YHeqVlKXSACu1myt13Cc1GW6ynnFrIjK4ouSzFZ/vlNsskgAytqD1d6Q3+Kevsl/xb951+OXyt6FstVytNRzAIS0S4i2S5u8TK3NXrPOZ57CYqLGXWiqOoi4Rz9UYMGpm241AAAAAElFTkSuQmCC';
width: 640;
height: 514;
quality: 60;
}
Alternatively, it can also be used through a provided component to automatically generate the proper HTML for including the image and its placeholder:
---
import { Image } from 'astro-eleventy-img';
---
<Image src="src/assets/my_image.png" alt="My super image!" caption="This is my favorite image." />
will generate the following HTML:
<figure>
<picture>
<source type="image/avif" srcset="/assets/images/4dWK95ygTq-640.avif 640w" />
<source type="image/webp" srcset="/assets/images/4dWK95ygTq-640.webp 640w" />
<img
alt="My super image!"
loading="lazy"
decoding="async"
style="
background-size: cover;
background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAkAAAAHCAIAAABV+fA3AAAACXBIWXMAAAsTAAALEwEAmpwYAAAAz0lEQVQImQHEADv/AJ7Ho7PYwTt5UhdkNjmLSUOPUCB4MSFzMkGMNACixqksb04WUy4wdz9cnFxPnksbaS0HTCo3hDUAnLmcRnFLQ289ZpZXn7Z9MpA+OYU9EFstVZpHAJ3GaqnPbJXFW5iyZNzLqZWvco+9YHeqVlKXSACu1myt13Cc1GW6ynnFrIjK4ouSzFZ/vlNsskgAytqD1d6Q3+Kevsl/xb951+OXyt6FstVytNRzAIS0S4i2S5u8TK3NXrPOZ57CYqLGXWiqOoi4Rz9UYMGpm241AAAAAElFTkSuQmCC);
"
onload="this.style.backgroundImage='none'"
src="/assets/images/4dWK95ygTq-640.png"
width="640"
height="514"
/>
</picture>
<figcaption>
<p>This is my favorite image.</p>
</figcaption>
</figure>
and the following files will be generated in the public/assets/images
folder:
4dWK95ygTq-640.avif
4dWK95ygTq-640.webp
4dWK95ygTq-640.png
The included Image
component is a thin wrapper around generateImage
and generatePlaceholder
, it works for most needs but do not hesitate to build your own!
Make sure to add the following to your astro.config.js
config:
vite: {
ssr: {
external: ["@11ty/eleventy-img"],
},
},