Performance
Largest Contentful Paint (LCP)
A Core Web Vital measuring how long the largest visible element, usually a hero image or headline, takes to render. The clearest proxy for perceived load speed.
Largest Contentful Paint records the moment the biggest element in the opening view finishes rendering, typically a hero image, a video poster, or a large block of headline text. It maps closely to a visitor’s gut sense that the page has loaded.
A good LCP is 2.5 seconds or faster on mobile. The usual causes of a slow score are oversized or unoptimised images, render-blocking CSS and JavaScript, slow server response, and fonts that delay text from painting.
The fixes are well understood: serve responsive, modern-format images, preload the LCP resource, inline critical CSS and defer the rest, and cut unused JavaScript. On migration projects we routinely move LCP from over four seconds into the sub-second range, which is often the difference between a visitor staying and bouncing.