Hints

Three event lanes compare plain fetching after a click, hinted fetching before it, and unused fetching two assets while only hero is consumed. The divider is an event boundary, not a measured time scale.

Preload gives crucial assets a head start

A preload announces a resource before its normal consumer discovers it. This can help when a needed image is created by JavaScript or a font is discovered only after loading and parsing a stylesheet. The benefit is an earlier opportunity to fetch. It does not follow that every hinted asset becomes the browser’s highest priority or that every page becomes faster. ...