One of Google's Core Web Vitals. Measures the render time of the largest content element visible in the viewport and is a proxy for perceived page performance. Google rewards pages with LCP below 2.5 s with higher SERP positions; studies also show that lower LCP correlates with higher conversion rate (approaching zero LCP is ideal). The subject of Paweł Pokrywka's wroclove.rb 2024 talk, where Signed Exchanges bring LCP to ~140 ms on throttled 3G.