ominou5 Page Speed Optimization
Every funnel page must load fast. Slow pages kill conversions — a 1-second delay reduces conversions by 7%.
Core Web Vitals Targets
| Metric | Target | Impact |
|---|---|---|
| LCP (Largest Contentful Paint) | < 2.5s | Main content visible |
| FID (First Input Delay) | < 100ms | Page is interactive |
| CLS (Cumulative Layout Shift) | < 0.1 | No visual jumping |
| TTFB (Time to First Byte) | < 800ms | Server responds fast |
Required Optimizations
1. Critical CSS Inlining
Inline above-the-fold CSS directly in <head> to eliminate render-blocking:
<head>
<style>
/* Critical: hero, nav, above-fold layout only */
.hero { /* ... */ }
.nav { /* ... */ }
.cta-primary { /* ... */ }
</style>
<!-- Defer the rest -->
<link rel="preload" href="styles.css" as="style"
<noscript><link rel="stylesheet" href="styles.css"></noscript>
</head>
2. Image Optimization
<!-- Always include width/height to prevent CLS -->
<img
src="hero.webp"
alt="Descriptive alt text"
width="800"
height="450"
loading="lazy"
decoding="async"
>
<!-- Responsive images with srcset -->
<img
srcset="hero-400.webp 400w, hero-800.webp 800w, hero-1200.webp 1200w"
sizes="(max-width: 600px) 400px, (max-width: 1000px) 800px, 1200px"
src="hero-800.webp"
alt="Descriptive alt text"
width="800"
height="450"
loading="lazy"
>
3. Font Loading
@font-face {
font-family: 'BrandFont';
src: url('brand-font.woff2') format('woff2');
font-display: swap; /* Always include this */
font-weight: 400;
}
<!-- Preload critical fonts -->
<link rel="preload" href="brand-font.woff2" as="font" type="font/woff2" crossorigin>
4. Script Loading
<!-- Defer non-critical scripts -->
<script defer src="analytics.js"></script>
<script defer src="interactions.js"></script>
<!-- Async for independent scripts -->
<script async src="third-party-widget.js"></script>
<!-- Never do this -->
<!-- <script src="blocking.js"></script> in <head> -->
5. Preconnect to Third Parties
<head>
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="preconnect" href="https://www.googletagmanager.com">
</head>
Performance Budget
| Resource | Budget |
|---|---|
| Total page weight | < 500KB |
| HTML | < 50KB |
| CSS | < 50KB |
| JavaScript | < 100KB |
| Images (above fold) | < 200KB |
| Fonts | < 100KB |
| Third-party scripts | < 50KB |
Quick Audit Checklist
- Viewport meta tag present
- All images have width/height attributes
- Below-fold images use
loading="lazy" - No render-blocking scripts in
<head> -
font-display: swapon all @font-face - Critical CSS inlined
- Third-party origins preconnected
- No unused CSS/JS shipped
- Images in WebP/AVIF format
- Total page weight under 500KB