The Largest Contentful Paint (LCP) metric reports the render time of the largest image or text block visible within the viewport. The viewport is everything that fits onto the visitor's screen. The time it takes to load the largest element within that area, whether it's an image, a video, or a block of text is the LCP. To summarize: LCP is how much time it takes before the visitor sees the most important content on his screen. Anything that's not directly in the viewport, is not included in this calculation.