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Sizes Attribute for Early Hints
Early hints image preloads now support a configurable sizes attribute, so browsers can pick the right srcset width for each viewport instead of guessing. Set a media query like (max-width: 600px) 100vw, 50vw from Configure → Performance, or override it per request via responseOptions.mediaPreloads.sizes. Layers sends it as the imagesizes attribute on the preload Link header, right alongside your existing srcset sizes.
ImprovementAPIPerformanceEarly Hints