Time To First Byte

Last Modified:
Apr 12, 2024 @ 9:28 am


Time to First Byte (TTFB) refers to the time between the browser requesting a resource (i.e., a webpage, a manifest, a video ) and when it receives the first byte of information from the server. This time includes DNS lookup and establishing the connection using a TCP handshake and  handshake if the request is made over .

TTFB is the time it takes between the start of the request and the start of the response, in milliseconds: TTFB = responseStart – navigationStart

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