The TTFB (Time To First Byte) is a metric in network metrology. It is the time elapsed between the opening of a TCP connection between a client and a server, and receipt by the client of a first packet with payload from the server.
A common measure
The TTFB is a common measure in metrology, this for two reasons.
The first is that it covers a number of possible causes of performance problems. As shown in the diagram above, the TTFB contains a part of…