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Performance
What is TTFB, and what does server response time say about a website?
TTFB (Time to First Byte) measures the time from opening a page to the arrival of the first bit of data from the server — Google rates up to 0.8 seconds as good, above 1.8 seconds as poor. The value is the foundation of every other load-time measurement: before the first byte arrives, the browser can't render anything. A slow server makes even the best-built page slow.
The server response is the start of every load time
The sequence behind every page load: the browser sends a request to the server, the server assembles the page and starts responding. The time until the first byte arrives is TTFB. An everyday comparison: you call a shop, and TTFB is the time until someone even picks up — before the conversation even begins. Everything after that, from the first visible content to the finished page build, can only start after this moment. That's why a poor TTFB automatically drags every subsequent value, like FCP and LCP, down with it.
Causes lie with hosting, software, or distance
Three things determine the response time. First, hosting: an overloaded budget plan, where many websites share one server, responds sluggishly. Second, software: if the system has to reassemble every page from the database on every request instead of delivering a ready-made copy, that costs time for every single visitor — caching fixes exactly that. Third, distance: if the server is on another continent, the data packet itself takes noticeably longer. Which of these causes falls to your agency and which to the hosting provider is usually clarified in the first conversation about the measured value.
The Google thresholds: 0.8 and 1.8 seconds
Up to 800 milliseconds, TTFB counts as good, up to 1800 milliseconds as needs improvement, above that as poor. The audit service draws the value from field data of real visitors over the last 28 days, if your page has enough views — this also shows how the server responds under real load, not just at the most favourable moment. The lab measures under fixed conditions in addition. Every value above the threshold appears as a finding in the report, with the measured value, source, and target value. That gives you a number instead of a feeling for the conversation with your hosting provider.
- Check TTFB first in the report before talking about images or design — if the server response is already slow, that's where the work starts.
- Ask your hosting provider whether your website is on a shared server and what faster tier would be available.
- Ask your agency to set up caching, so the server delivers ready-made pages instead of recalculating every request.
- Find out which country your server is in — for visitors from Austria and Germany, it belongs in Europe.
- Compare TTFB at different times of day, since a server that's only slow in the evening is simply overloaded.
FAQ
What does TTFB mean for a website?
TTFB stands for Time to First Byte: the time from sending the request to the arrival of the first bit of data from the server. The value measures how fast the server even starts to respond — before anything becomes visible at all. All further loading steps can only start after this moment, so a poor TTFB affects the entire load time.
What TTFB value is good?
Google rates a TTFB up to 800 milliseconds as good, up to 1800 milliseconds as needs improvement, and above that as poor. The audit service checks against exactly these thresholds and prefers field data from real visitors over the 28-day window, since it shows the server under real load, not just at the most favourable moment.
How can I improve my website's server response time?
The three most effective levers: set up caching, so the server delivers ready-made pages instead of recalculating every one; check the hosting plan, since overloaded shared servers respond sluggishly; and locate the server close to your visitors. Which lever applies to you is best discussed with your agency and hosting provider based on the measured value.
Is a slow website caused by the server or by the page itself?
TTFB answers exactly this question. If it's poor, the page loses its time right at the server — hosting and caching are then the first place to start. If TTFB is good but the page is still slow, it's down to what comes after: oversized images, blocking scripts, heavy rendering. The audit report shows both values side by side.