The Keep-Alive general header allows the sender to hint about how the connection may be used to set a timeout and a maximum amount of requests.
Note: Set the Connection header to "keep-alive" for this header to have any effect.
Warning: Connection-specific header fields such as Connection and Keep-Alive are prohibited in HTTP/2 and HTTP/3. Chrome and Firefox ignore them in HTTP/2 responses, but Safari conforms to the HTTP/2 specification requirements and does not load any response that contains them.
A comma-separated list of parameters, each consisting of an identifier and a value separated by the equal sign ('='). The following identifiers are possible:
timeout: An integer that is the time in seconds that the host will allow an idle connection to remain open before it is closed. A connection is idle if no data is sent or received by a host. A host may keep an idle connection open for longer than timeout seconds, but the host should attempt to retain a connection for at least timeout seconds.
max: An integer that is the maximum number of requests that can be sent on this connection before closing it. Unless 0, this value is ignored for non-pipelined connections as another request will be sent in the next response. An HTTP pipeline can use it to limit the pipelining.