Time to First Byte (TTFB) is a measure used to assess the responsiveness of a web server. It represents the time from the user's request to the first byte of the page being received by the browser. TTFB is a critical metric in web performance, as a lower TTFB means a faster start to loading a web page, leading to an improved user experience.

Factors Impacting Time to First Byte (TTFB)

The following factors have direct impact on the TTFB of a website:

1. DNS Lookup

Description: Resolving the domain name to an IP address.
Impact: Delays if DNS server is slow or domain name not cached.

2. TCP Connection

Description: Establishing a TCP connection with the server.
Impact: Affected by network latency and server load.

3. SSL/TLS Handshake

Description: Additional handshake for secure (HTTPS) connections.
Impact: Adds delay, especially with poor SSL/TLS setup.

4. Server Processing Time

Description: Time taken by the server to process the request.
Impact: Depends on server load, server-side scripts, database queries, and backend processing.

5. Network Latency

Description: Distance between user and server.
Impact: Longer distances increase data travel time.