Which Core Web Vital is related to loading performance?

The Largest Contentful Paint (LCP) is a key metric that measures loading performance by assessing how quickly the largest content element on the page becomes visible to users. It focuses on the time it takes for the most significant piece of content, such as an image or a large block of text, to load and render within the viewport after the user initiates navigation. A fast LCP indicates that the page is loading quickly and provides a better user experience as it signifies that users can view the main content promptly.

In the context of user experience and performance optimization, LCP is crucial because it directly impacts how users perceive the speed of a website. If this metric is not optimized, users may become frustrated due to slow loading times, leading to higher bounce rates and potential loss of engagement.

The other metrics mentioned, while also important for user experience, focus on different elements of website performance. First Input Delay measures responsiveness to user interactions, Time to Interactive assesses the time it takes for a page to become fully interactive, and First Contentful Paint looks at when the first pieces of content are displayed. While these metrics are interconnected, LCP specifically targets the loading performance of the largest visible content, making it the most relevant choice regarding loading performance.