Speed IndexWhat it checks and how to fix it

What it checks

Reads Speed Index, how quickly the visible part of the page fills in during load, from a Lighthouse mobile run on the page. Under 3.4 s passes, under 5.8 s warns, and 5.8 s or more fails. It runs on the pages chosen for Lighthouse.

Why it matters

Speed Index captures how fast the page looks complete, not just when the first pixel appears. A page whose content trickles in over several seconds feels slow even if it starts painting early, and visitors judge the site by that impression.

How to fix it

Get the content above the fold painted early and in one go:

• Prioritize the hero image and above-the-fold content; lazy-load everything below the fold.
• Inline critical CSS and defer non-essential JavaScript.
• Avoid rendering the first screen on the client when it can be server-rendered.
• Reduce the main-thread work that delays painting, including third-party scripts.

<img src="/images/hero.webp" alt="Hero" width="1200" height="630" fetchpriority="high">
<img src="/images/footer-map.webp" alt="Office map" width="600" height="400" loading="lazy">