Core Web Vitals
Check LCP, CLS and INP of a URL — based on real field data.
Field data instead of lab values: Real-User Monitoring (RUM)
This check uses aggregated field data — measurements from your visitors' real browsers, not a synthetic lab test. Google rates Core Web Vitals at the 75th percentile: the value 75 % of your page loads reach or beat. In the XICTRAQ dashboard the same RUM view is additionally segmented by device type, page and country, showing the "good / needs-improvement / poor" distribution per metric.
Responsiveness signal: measures the delay across all interactions. Replaced FID in March 2024 — good ≤ 200 ms.
Loading perception: when the largest element becomes visible — good ≤ 2.5 s.
Visual stability: unexpected layout shifts — good ≤ 0.1.
How this tool works
Core Web Vitals shows the three Google ranking metrics LCP (Largest Contentful Paint), CLS (Cumulative Layout Shift) and INP (Interaction to Next Paint) based on real Chrome user data (CrUX). You see the 75th percentiles — the experience 75% of your visitors have or better.
Typical use cases
- Before relaunch, document Web Vitals baseline
- After performance optimizations, check if CrUX data improved
- Competitor analysis: compare own vitals with competition
- SEO reporting: document Web Vitals as ranking factor
Frequently asked questions
What are good Core Web Vitals values?
LCP below 2.5s = good, CLS below 0.1 = good, INP below 200ms = good. Values above are "needs improvement" or "poor".
Why is no data shown?
CrUX requires sufficient Chrome user traffic. Small websites or new domains often have no field data — then values remain empty.
What is the difference between URL and origin data?
URL data is specific to the checked URL. Origin data is aggregated over the entire domain (28 days). Origin more often has data available.
Are Core Web Vitals a ranking factor?
Yes — official Google ranking factor since 2021. Poor vitals do not cause drastic ranking losses, but with equally relevant pages Google prefers the faster one.
What did INP replace?
INP replaced FID (First Input Delay) in March 2024. INP measures overall interactivity, not just the first input.
How can I improve LCP?
Load largest element faster: optimize hero image (WebP, preload), speed up server response (TTFB < 800ms), eliminate render-blocking CSS/JS.
Related tools
Continuous monitoring vs. one-shot?
XICTRAQ monitors uptime, SSL, security headers, GDPR and performance 24/7. Free plan, no credit card.