Chrome’s Native Image Lazy Loading Fetches Too Far Ahead
In a recent analysis, Aaron Peters documents how Chrome’s native loading="lazy" attribute behaves far more eagerly than expected. On a 13-inch MacBook with the Dock on the left, Chrome reports a viewport height of 786 pixels. Peters found that images located more than 4x the viewport height down the page are still fetched immediately on load — a threshold he calls “waaaay too eager.” He suggests a fixed 1000-pixel threshold or, better, tying the cutoff to the actual computed viewport height.
The author of the original piece speculates Chrome chose a generous margin to avoid over-engineering the initial implementation, accepting that a high fetch distance lowers the risk of visible layout shifts on pages where images lack explicit width and height attributes. The closest thing to a spec appears to be an unmerged WHATWG pull request, whose language — “scrolled into the viewport” — implies no threshold distance at all, a stark contrast to current browser behavior.
