Web Analytics Patterns

Core Web Vitals Debugging

Dashboard → Core Web Vitals → Click metric → Debug View shows top 5 problematic elements.

LCP Fixes

<!-- Priority hints -->
<img src="hero.jpg" loading="eager" fetchpriority="high" />
<link rel="preload" as="image" href="/hero.jpg" fetchpriority="high" />

CLS Fixes

/* Reserve space */
.ad-container { min-height: 250px; }
img { width: 400px; height: 300px; } /* Explicit dimensions */

INP Fixes

// Debounce expensive operations
const handleInput = debounce(search, 300);

// Yield to main thread
await task(); await new Promise(r => setTimeout(r, 0)); await task2();

// Move to Web Worker for heavy computation

Metric	Good	Poor
LCP	≤2.5s	>4s
INP	≤200ms	>500ms
CLS	≤0.1	>0.25

// Load beacon only after consent
const consent = localStorage.getItem('analytics-consent');
if (consent === 'accepted') {
  const script = document.createElement('script');
  script.src = 'https://static.cloudflareinsights.com/beacon.min.js';
  script.setAttribute('data-cf-beacon', '{"token": "TOKEN", "spa": true}');
  document.body.appendChild(script);
}

Alternative: Dashboard → "Enable, excluding visitor data in the EU"

<!-- REQUIRED for React/Vue/etc routing -->
<script data-cf-beacon='{"token": "TOKEN", "spa": true}' ...></script>

Without spa: true: only initial pageload tracked.

Staging/Production Separation

// Use env-specific tokens
const token = process.env.NEXT_PUBLIC_CF_ANALYTICS_TOKEN;
// .env.production: production token
// .env.staging: staging token (or empty to disable)

Bot Filtering

Dashboard → Filters → "Exclude Bot Traffic"

Filters: Search crawlers, monitoring services, known bots.
Not filtered: Headless browsers (Playwright/Puppeteer).

Ad-Blocker Impact

~25-40% of users may block cloudflareinsights.com. No official workaround. Dashboard shows minimum baseline; use server logs for complete picture.

Limitations

No UTM parameter tracking
No webhooks/alerts/API
No custom beacon domains
Max 10 non-proxied sites

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