# Landing page load performance is optimized
- **Pattern:** `ab-001759` (`marketing-conversion.conversion-infrastructure.conversion-load-performance`)
- **Severity:** high
- **Lifecycle:** active
- **Last modified:** 2026-04-18
- **Canonical URL:** https://auditbuffet.com/patterns/ab-001759
- **License:** CC-BY-4.0 — attribute to AuditBuffet Pattern Catalog (https://auditbuffet.com/patterns/ab-001759)
## Why it matters
Every additional 100ms of Largest Contentful Paint degrades conversion rate — Google's own data shows a 1-second LCP delay can reduce conversions by up to 7%. The most common source of above-fold slowness in Next.js marketing pages is a hero image loaded with default lazy behavior (which defers it) and synchronous third-party scripts blocking the render path. Render-blocking analytics, chat, and A/B testing scripts compound the problem because they delay the browser's ability to paint anything the user can interact with. ISO 25010:2011 performance-efficiency directly covers time-behavior under load.
## Severity rationale
High because above-fold load performance has a direct, measurable impact on conversion rate and is routinely the largest single contributor to poor Core Web Vitals scores on marketing pages.
## Remediation
Prioritize the above-fold hero image and defer non-critical third-party scripts. Two targeted fixes cover the most common cases:
```tsx
// 1. Add priority to the hero image so the browser fetches it immediately
// 2. Defer analytics and chat scripts so they don't block render
```
Also confirm `font-display: swap` is set in your font configuration (e.g., in `src/app/layout.tsx` via `next/font`) so text renders immediately in a fallback font rather than staying invisible during the web font download.
## Detection
- **ID:** `conversion-load-performance`
- **Severity:** `high`
- **What to look for:** Examine the landing page component for patterns that impact initial load time and perceived performance. Check: (1) Images in the hero section — do they use Next.js `` component with `priority` prop for the above-fold hero image? (2) Large JavaScript bundles — check for heavy libraries imported directly in marketing page components that could be lazy-loaded; (3) Third-party scripts — count analytics, chat, A/B testing scripts loaded synchronously in `` or root layout; (4) Font loading — check for `font-display: swap` in font configuration to prevent invisible text during load; (5) Check `next.config.*` for image optimization settings if Next.js is used.
- **Pass criteria:** Count all blocking resources in the document head (synchronous scripts, render-blocking CSS). The above-fold hero image (if any) uses `priority` loading or eager loading. No more than 3 synchronous third-party scripts in the document head. Font loading does not block render (uses `font-display: swap` or equivalent). Report: "X blocking resources found in document head."
- **Fail criteria:** Hero section images use default lazy loading (which defers above-fold images unnecessarily). OR more than 3 synchronous blocking scripts in the document head. OR no font-display strategy detected and multiple custom web fonts are loaded.
- **Skip (N/A) when:** The project uses a purely text-based hero (no images) and has no third-party scripts. In this case, skip with note that common load blockers are not present.
- **Detail on fail:** Describe specific findings. Example: `"Hero component missing priority prop — above-fold image will be lazy-loaded, increasing LCP."` or `"4 synchronous third-party scripts in root layout head (analytics, chat, heatmap, A/B test tool) — blocking render."`.
- **Remediation:** Every 100ms of additional load time reduces conversion rates. Focus on what visitors see first:
```tsx
// Hero image: add priority to load it eagerly
```
For third-party scripts, defer non-critical ones:
```tsx
// In Next.js, use Script component with strategy
```
For a deeper analysis of Core Web Vitals and load performance, the Page Speed & Load Readiness audit examines bundle size, image optimization, and performance budgets in detail.
## External references
- iso-25010 performance-efficiency
Taxons: performance
HTML version: https://auditbuffet.com/patterns/ab-001759