<img> loading - best practices

HTML elements

• picture
• source

HTML attributes

• type
• srcset
• sizes
• loading
• decoding

All together

<picture>
  <source 
    type="image/avif"
    srcset="/image.avif?width=100 100w, /image.avif?width=200 200w, /image.avif?width=400 400w, /image.avif?width=800 800w" />
  <source 
    type="image/webp"
    srcset="/image.webp?width=100 100w, /image.webp?width=200 200w, /image.webp?width=400 400w, /image.webp?width=800 800w" />
  <img 
    src="/image.png"
    srcset="/image.png?width=100 100w, /image.png?width=200 200w, /image.png?width=400 400w, /image.png?width=800 800w"
    sizes="(max-width: 800px) 100vw, 50vw"
    style="width: 100%; aspect-ratio: 16/9"
    loading="lazy"
    decoding="async"
    alt="Builder.io drag and drop interface"
  />
</picture>

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Source: builder.io.