Page speed test — Core Web Vitals and heavy assets

Check LCP, INP, CLS, TTFB, page weight, request count, caching and compression. The report separates real-user data from the lab run and shows the evidence worth starting from.

What the speed test measures

Core Web Vitals — We show LCP, INP and CLS from CrUX field data whenever Google has a large enough sample. Otherwise the report labels the figure as a lab measurement, or as no data at all.

Response and loading — Home-page TTFB, download time, and the render-blocking resources that delay the moment your main content appears.

Weight and requests — HTML, CSS, JavaScript, images and fonts, counted. We point out heavy assets, missing compression, absent caching and images not served in a modern format.

The server layer — Compression, cache headers, HTTP/2 or HTTP/3 support and CDN fingerprints — enough to separate a front-end problem from a hosting one.

The PageSpeed measurement applies to one entry URL; the scanner additionally discovers representative sub-pages. We do not collect your own Web Vitals from visitors' browsers — that needs measurement built into the site itself. Weightings and thresholds are in the methodology.

How caching shortens the path for every asset

Cache-Control headers decide whether a file is taken from browser memory, served by a CDN, or regenerated on the origin server. The report lists the assets that are not taking the shorter route.

Field tells you what people experienced; lab tells you what to debug today

CrUX aggregates the previous 28 days and may hold no data for a small site. Lighthouse performs a single controlled test. The two can disagree, both are useful, and they answer different questions.

Frequently asked questions

What counts as a fast site? In Core Web Vitals the good thresholds are LCP under 2.5 s, INP under 200 ms and CLS under 0.1, assessed at the 75th percentile of visits. A green 90/100 in Lighthouse is a good lab result, but it does not replace data from real users.

Why does this differ from PageSpeed Insights? Individual lab tests depend on location, server load and simulated conditions. Field data aggregates 28 days of real user experience. SEOMaster labels the source of each metric and adds its own measurement of assets and server behaviour.

Why can't I see INP or CrUX data? A new or rarely visited site may not have a large enough sample for the public CrUX report. Missing field data is neither a good nor a bad result — use the lab diagnostics and start collecting your own Web Vitals.

Does the test only cover the home page? The PageSpeed measurement applies to a specific entry URL, while the scanner additionally discovers representative sub-pages and analyses their assets, images and technical signals. For key templates it is worth running separate tests.

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