TTFB checker

What TTFB measures

Time to First Byte (TTFB) is the interval between a browser sending a request and receiving the first byte of the response from the server. It reflects a combination of network latency, server processing time, and any backend work required to prepare the response, such as database queries or cache lookups.

Reading TTFB values

Lower values indicate a faster initial response. General guidance suggests that a TTFB under 200 milliseconds is good, while values above 600 milliseconds warrant investigation. These thresholds are not absolute, because network distance and connection type influence the result. A TTFB that is high from one location but low from another may point to routing or CDN configuration rather than server performance.

What influences TTFB

• Server processing. Application logic, database queries, and cache misses increase the time before a response starts.
• Network latency. Geographic distance, connection quality, and routing between client and server add delay.
• CDN and caching. A well-configured CDN can reduce TTFB by serving content from a location closer to the user.
• Backend dependencies. External API calls or third-party services during page generation can delay the first byte.

Limitations

This tool measures TTFB from a single point of observation and reports the value for one request. Results vary with network conditions, server load, and caching state. TTFB is only one part of page performance; it does not measure how long the full page takes to render or how resources load. Use it as a diagnostic signal for server and network response, not as a complete performance assessment.