[kmlx]

yes, there is already

<img loading="lazy" ... />

simply add the property to your html images and the browser will automatically load them when in the viewport (i.e. just the ones you actually see)

further details: https://caniuse.com/#feat=loading-lazy-attr

https://html.spec.whatwg.org/multipage/urls-and-fetching.htm...

[Wowfunhappy]

But then they always seem to not come in until I scroll to them, which is too late and just means I have to wait even more! What they ought to do is download as soon as the network is quiet.