Website speed test methodology
What this tool measures, what it does not, and how a score or grade is produced.
Test region: Germany (PK Hosting application server)
What we measure
Time to first byte, HTML download time, HTML size and a rough count of referenced resources, measured from our application server.
What we do not measure
Real-user Chrome UX, LCP, INP, CLS, TLS handshake quality from every city, CDN edge performance, or frontend rendering. Performance also depends on DNS, TLS, backend processing, caching, CDN and the page itself.
How we calculate this
TTFB is one useful measure of how quickly the server begins responding. Grades AβD use TTFB, total HTML fetch time and HTML size thresholds measured from this region β they are not Core Web Vitals.