408 Request Timeout
Meaning
The server timed out waiting for the request. The client did not produce a request within the time that the server was prepared to wait.
When to Use
When the server closes the connection due to a client’s slow request or inactivity. It indicates that the client may retry the request at a later time without modifications.
Example
If a client begins a request but stops sending data for too long, the server may respond with 408 Request Timeout and close the connection to free up resources.
When Not to Use
Do not use if the server has received and is processing the request (then the response should be based on that processing, not a timeout). Typically, 408 is generated by the server automatically rather than by application logic.
Source
RFC 9110