PageSpeed Insights 90+: How to Get There on OpenCart / WordPress

PageSpeed 90+ is a genuinely achievable target for any PHP site. Here is a step-by-step plan, ordered from the biggest impact down to the details.

The steps, most important first

1. TTFB — server response time (the biggest lever)

Target: TTFB under 200 ms. What it takes:

• a Redis cache for OpenCart/WordPress
• Nginx FastCGI cache or Varnish for static pages
• the Cloudflare CDN — caching at the edge

2. LCP — the largest contentful element

Usually the hero image. The fix:

<link rel="preload" href="hero.webp" as="image" fetchpriority="high">
<img src="hero.webp" loading="eager" fetchpriority="high">

3. Render-blocking resources

<!-- Instead of: -->
<script src="app.js"></script>
<!-- Use: -->
<script src="app.js" defer></script>

4. Images — WebP and lazy loading

Convert every image to WebP (2–3× smaller). In Nginx:

map $http_accept $webp_suffix {
  "~*webp" ".webp";
}

5. Unused CSS/JS

Use the Chrome Coverage tab to find unused CSS and JS. PurgeCSS works well for WordPress themes.

Real-world results

OpenCart with Redis + Nginx cache + WebP: Mobile 85–92, Desktop 96–99.
WordPress with LiteSpeed Cache + WebP: Mobile 88–93, Desktop 95–98.

Need this optimisation? PageSpeed 90+ for your site.