TTFB (Time To First Byte) — the time from sending a request to receiving the first byte of the server's response.
Includes RTT, TLS handshake, and CDN-side request processing time.
TTFB directly affects:
page load speed as assessed by Google (Core Web Vitals)
website rankings in search results
the user's perception of site speed
Google recommends keeping TTFB below 800 ms. Values above this threshold negatively impact search rankings.
What do the TTFB charts show?
Average connection time trend chart (HTTP/HTTPS) — the difference between HTTP and HTTPS reflects the overhead of the TLS handshake. A large gap between the lines indicates a suboptimal SSL configuration on the provider's edge servers.
Cities with high TTFB — locations where the CDN server processes requests slowly. May indicate insufficient capacity at regional nodes or frequent cache misses.
Providers with high TTFB — a comparative response speed ranking. Low TTFB correlates with better search rankings and higher conversion rates.
