LCP (Largest Contentful Paint): definition and optimization
Definition
LCP (Largest Contentful Paint) measures the time needed to display the page's largest visible element—often an image. It's one of Google's Core Web Vitals.
A good LCP is under 2.5 seconds. Since the LCP element is often an image (banner, product visual, header photo), its size and format directly impact the score. Reducing that image's weight and serving it in the right format is one of the most effective ways to improve it.
Key points
Weight matters
An LCP image that's too heavy delays display. Converting to WebP/AVIF greatly reduces render time.
Right size
Serving the image at exactly the displayed dimension avoids downloading unnecessary pixels.
Proximity matters
Serving the image from a CDN close to the visitor reduces latency, thus LCP.
