How to Monitor Core Web Vitals from Real Users with statpx
Lighthouse scores are useful. PageSpeed Insights is useful. But neither tells you what your actual visitors experience when they load your site on their device, their network, their browser, with their browser extensions installed.
Core Web Vitals measured from real users — called Real User Monitoring (RUM) — are what Google actually uses to rank your site. statpx captures LCP, CLS, and INP from every visitor's browser automatically, and presents them in a dedicated Site Speed dashboard.
What Are Core Web Vitals?
Core Web Vitals are three browser metrics that Google defined as the key indicators of a good user experience:
| Metric | What It Measures | Good | Needs Work | Poor |
|---|---|---|---|---|
| LCP — Largest Contentful Paint | How fast your main content loads | < 2.5s | 2.5–4.0s | > 4.0s |
| CLS — Cumulative Layout Shift | How much the page layout shifts unexpectedly | < 0.1 | 0.1–0.25 | > 0.25 |
| INP — Interaction to Next Paint | How fast the page responds to user input | < 200ms | 200–500ms | > 500ms |
Google uses the 75th percentile of real user data when determining your site's ranking. This means 75% of your visitors need to have a "Good" experience for your site to be considered compliant — one fast page load doesn't cancel out three slow ones.
The statpx Site Speed Dashboard
Open any site in statpx and click Site Speed in the left sidebar. The dashboard shows:
Summary Metric Cards
Three large cards show your average LCP, CLS, and INP for the selected period, color-coded green / amber / red based on Google's thresholds. Each card also shows the p75 value (when enough data is available) and a distribution bar showing what percentage of sessions fell into Good, Needs Work, and Poor buckets.
LCP Trend Chart
The trend line shows your average LCP over time — daily for multi-day ranges, hourly for today. Use this to spot when a deployment caused a regression or when a CDN configuration change improved your scores.
Slowest Pages by LCP
The per-page table ranks every URL by its average LCP, with CLS and INP alongside. This is where you find the highest-impact optimization targets. A page with 5,000 monthly visits and a Poor LCP is worth more of your time than a rarely visited page with a Perfect score.
Performance by Device
Mobile and desktop users experience dramatically different performance. A page with a Good LCP on desktop can easily be Poor on a mid-range Android device on mobile data. The device breakdown shows your CWV scores separately for mobile, tablet, and desktop — so you can prioritize mobile-first optimizations where they matter most.
See your real-user performance data
statpx captures Core Web Vitals from every visitor automatically — no extra code, no Lighthouse CLI, no separate RUM tool.
Start monitoring for free →How statpx Captures CWV Data
The statpx tracking script uses the browser's PerformanceObserver API to observe largest-contentful-paint, layout-shift, and event (for INP) entries. Data is collected as the page loads and after user interaction, then sent to statpx in a single small payload. This adds less than 1ms of overhead and has no measurable impact on the very metrics it measures.
Bots and crawlers are excluded from CWV data. Only real human sessions contribute to your averages — so you see what your users actually experience, not what Googlebot sees.
Synthetic vs Real User Monitoring: Why Both Matter
Lighthouse and PageSpeed Insights run in a controlled environment: fixed network speed, fixed CPU, no browser extensions, no cached resources. They're great for catching regressions before deployment. But real users have slow connections, loaded browser caches, different devices, and extensions that inject CSS and scripts.
statpx's Site Speed dashboard shows you the real picture — what your actual users experience, including the long tail of slow connections that synthetic tools miss. The two approaches complement each other: use PageSpeed Insights to debug and optimize, use statpx to verify that real users actually benefit from your changes.
Using CWV Data to Prioritize Fixes
When you open the slowest pages table, sort by LCP. The top entries are your highest-priority optimization targets. Common LCP improvements include:
- Serving images in WebP or AVIF format with proper sizing
- Adding
loading="eager"andfetchpriority="high"to above-the-fold images - Using a CDN to reduce server response time
- Preloading critical CSS and fonts
For CLS, high scores usually point to images without width/height attributes, dynamically injected content (ads, cookie banners), or font swaps. For INP, look at heavy event listeners and long JavaScript tasks that block the main thread.
The Bottom Line
Synthetic performance scores tell you what could be better. Real-user CWV data tells you what's actually hurting your visitors — and your search rankings. statpx gives you both in one place, automatically, without any additional configuration.
Check your Site Speed dashboard today. The data starts accumulating the moment your snippet is installed.
Related: Core Web Vitals Explained: LCP, CLS, and INP for Site Owners