Methodology
turbometrics rates websites using the same terms and signals you see in the scan report: overall score, sub-scores, browser runtime measurement, biggest slowdowns, issues and recommendations.
In short: The score is a technical assessment built from preflight signals, browser runtime and specifically detected slowdowns. It is deliberately not an SEO ranking and does not replace looking at issues, recommendations and history.
Score component
The speed sub-score looks at server response, visible page build-up and browser runtime. Key signals include TTFB, FCP and LCP.
Score component
Images have a direct effect on LCP, data volume and load time. Large or poorly delivered image assets therefore often show up among the biggest slowdowns and recommendations.
Score component
Browser caching and cache quality per asset type influence how stable a site stays on repeat visits and how much load gets transferred again unnecessarily.
Score component
The WordPress and technology sub-scores bundle issues with themes, plugins, assets, requests, data volume, external services and technical delivery.
Score component
Blocking scripts, DOM size and the resource breakdown show how much JavaScript and CSS slow down page build-up and how much unnecessary load gets transferred.
Score component
Fonts directly affect the visible text build-up. Outdated formats like TTF or EOT, missing WOFF2 variants, missing font-display and large font files feed into the fonts sub-score.
Visible in the product
These key figures and signals reappear in the report
Time to First Byte
Shows how quickly the server responds to the first request. A high TTFB weakens the technical foundation for every step that follows.
First Contentful Paint
Measures when visible content first appears in the browser. A late FCP delays the first perceivable page build-up.
Largest Contentful Paint
Measures when the most important visible main content has loaded. LCP is especially prominent in the product because it strongly shapes the first impression.
Cumulative Layout Shift
Shows whether content jumps around while loading. A low CLS stands for a stable build-up without visible shifting.
Total Blocking Time
Measures how long the browser main thread was blocked during page build-up. High values point to heavy JavaScript load and directly affect perceived interactivity.
Total load in the browser
Many or large requests slow down the real page build-up. That is exactly why requests, bytes and the largest assets show up in several places in the report.
Desktop & Mobile
The runtime values show what actually happens during page build-up in the browser. Mobile and desktop differences are often more important than pure lab assumptions.
Prioritised bottlenecks
This area shows the most noticeable bottlenecks and the next sensible steps. This is usually the fastest place to see what is actually slowing things down and where to start.
Changes over time
Comparison and baseline help classify improvements or regressions over time properly, instead of just looking at a single value.
Browser main thread
Blocking tasks that delay page build-up. Recognisable by a long TBT and many main-thread blockages.
JS / CSS / IMG / FONT
Breakdown of loaded resources by type and weight. Helps identify which asset type slows things down the most.
Navigation Timing API
DNS lookup, TCP connection, TTFB, DOM load time and full load time — measured separately for desktop and mobile directly from the browser.
Rating
How to read the score
90–100
Very good
The site is technically very solid. Individual slowdowns and baseline changes are still worth keeping an eye on.
75–89
Good
The site is well set up overall. It is still worth looking at individual slowdowns, recommendations and baseline changes.
60–74
Room for improvement
There are clearly visible bottlenecks in load time, rendering, assets or delivery. The site is usable, but not yet reliably fast.
0–59
Critical
Several issues noticeably slow the site down, or the technical foundation is unstable. Prioritised action is advisable here.
Important: In a normal scan, overall and sub-scores are rated as very good, good, room for improvement or critical. In PDF and comparison views, we additionally describe the situation via action items, bottlenecks, baseline and prioritised recommendations.
Rating, not magic
What's behind the overall score
Prioritisation
Why issues and recommendations often matter more
Why values fluctuate
Single measurements are never the whole truth
In practice
Why repeated scans are more useful
A single scan is always just a snapshot. Only repeated or scheduled scans show whether a page is consistently fast or just happened to have a good or bad moment.
That is exactly why history, baseline, alerts and the comparison between individual scans are often more valuable than a single score without context.
Important clarification
What the score is and what it is not
What it is
A technical assessment to surface bottlenecks, prioritise actions and put changes into context via baseline, history and scheduled scans.
What it is not
Not a Google ranking, no SEO guarantee, and no mathematical promise that a single measurement precisely reflects every visitor situation.