FCP measures when a visitor sees that the page is starting to load. Until that moment, a blank screen is displayed.
FCP is not one of the three Core Web VitalsCore Web Vitals Three Google metrics that indicate how fast and user-friendly a page is for visitors., but it is shown alongside LCPLCP The time it takes for the largest visible element of a page to appear on the screen. in PageSpeed InsightsPageSpeed Insights A free tool from Google that measures page speed and provides tips for improvement..
