Free Core Web Vitals Test
Measure LCP, INP and CLS for any URL using Google's own data — and see exactly which images and scripts are dragging your scores down.
Core Web Vitals are the three metrics Google uses to judge real-world page experience — and they're a confirmed ranking factor. The siteIQ Core Web Vitals Test measures them using Google's PageSpeed data, so you see what Google sees.
Enter any URL to get your LCP, INP and CLS scores against Google's pass/fail thresholds, plus the specific elements causing each problem.
What this tool checks
LCP (loading)
Largest Contentful Paint — how fast your main content appears. Target under 2.5s.
INP (responsiveness)
Interaction to Next Paint — how quickly the page reacts to taps. Target under 200ms.
CLS (stability)
Cumulative Layout Shift — how much the layout jumps around. Target under 0.1.
Render-blocking resources
Scripts and styles delaying your first paint.
Image optimization
Oversized or unoptimized images hurting load time.
Why it matters
Speed isn't a vanity metric — it directly affects rankings, bounce rate and conversions. A one-second delay measurably reduces the number of people who stay and buy.
Because Core Web Vitals are a Google ranking signal, passing the assessment can give you an edge over competitors with slower, less stable pages targeting the same keywords.
How to read your results
- A metric is 'Good', 'Needs Improvement' or 'Poor' — aim for Good on all three.
- Poor LCP is usually a heavy hero image or slow server — compress images and use a CDN.
- Poor CLS is almost always images/ads without reserved space — set width and height on every image.
- Poor INP means too much JavaScript on the main thread — defer or remove non-essential scripts.
Frequently asked questions
Is this lab data or field data?
siteIQ uses Google PageSpeed Insights, which reports both lab data (a controlled test) and, when available, field data (real Chrome users). Google ranks on field data, so prioritize that.
What's a good Core Web Vitals score?
Pass means LCP under 2.5s, INP under 200ms and CLS under 0.1, for 75% of real visits. The report shows where you stand on each.
Why is my score different from another tool?
Scores vary with network, device and the exact moment of testing. Trust the trend and the field data over a single number.
How often should I test?
Test after any significant change to your site, and periodically — performance regresses over time as you add scripts, images and features.
Core Web Vitals Explained: How to Make Your Website Faster →
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