Every hosting provider publishes uptime statistics. Almost none publish TTFB benchmarks. This is not an accident.
Time to first byte is the duration between a browser sending a request and receiving the first byte of the server response. It is a direct measurement of server processing speed. It cannot be improved by compressing images, minifying JavaScript, or adding a CDN. It requires fixing the server itself.
The Google threshold for good TTFB is 800 milliseconds. The threshold for excellent TTFB is 200 milliseconds. The gap between these two numbers represents the difference between a server that is working and a server that is performing. Most shared hosting environments sit between 600 and 1,200 milliseconds. Most managed hosting environments that take performance seriously sit below 200 milliseconds.
What TTFB Actually Measures
TTFB is a composite measurement. It includes DNS resolution time, TCP connection time, TLS handshake time, server processing time, and network transit time. For a request to a properly configured server on a well-provisioned network, DNS, TCP, and TLS together should account for less than 100 milliseconds. The remainder is server processing time.
Server processing time includes PHP execution, database queries, cache lookups, and any external API calls in the critical path. A WordPress site with a warm full-page cache can respond in under 20 milliseconds of server processing time. The same site without caching, with unoptimised database queries, running on an underpowered server, can take 800 milliseconds or more.
The Conversion Impact
The relationship between page load time and conversion rate is well established. A 1-second delay in page load time reduces conversions by approximately 7%. A 2-second delay reduces them by 14%. These numbers compound across every page in the user journey. A checkout flow with five pages, each delayed by 1 second, represents a 35% conversion penalty before the user has made a single decision.
TTFB is the foundation of page load time. You cannot build a fast page on a slow server. Frontend optimisation on top of a high-TTFB server is the equivalent of painting a house that has structural problems. It looks better. It does not fix the underlying issue.
What to Ask Your Host
Ask your hosting provider for your current TTFB measured from your primary user geography. Ask what their target TTFB is for managed environments. Ask how they measure it and how frequently. If they cannot answer these questions, or if the answers are vague, that is the answer.
TTFB under 200 milliseconds is achievable on properly configured infrastructure. It requires correct server tuning, appropriate caching architecture, optimised database queries, and adequate hardware. None of these are exotic requirements. They are the baseline standard for hosting that takes performance seriously.