What could impact LCP?

To give an idea of LCP, the following could impact the largest contentful paint:

• Bad hosting or a heavy CMS, for example with quite a few plugins, are more likely to result in a higher server response time and thus TTFB metric. As a results, the browser will receive the HTML later in time, and thus the LCP will be shifted back as well;
• Render as well as parse blocking resources will prevent the browser to parse and render the HTML containing the largest element late in time;
• Slow resources, such as resources responsible for the largest elements but served with quite some network latency, will start later in the process;
• Not serving responsive and thus smaller images, for example on product detail pages or hero images on article pages;
• Client side rendering when this is delaying the layout and composition of the largest element within the viewport.