What status code is returned when http request times out?

When an HTTP request times out, the server may return different status codes, depending on the server's configuration and implementation. Here are some common possibilities:

1. 504 Gateway Timeout: This status code indicates that when the request was forwarded by the proxy server to the upstream server, the upstream server timed out and did not respond.

2. 408 Request Timeout: This status code indicates that the request sent by the client exceeds the time allowed by the server.

3. 502 Bad Gateway: This status code indicates that the gateway server received an invalid response from the upstream server while trying to complete the request.

4. 503 Service Unavailable: This status code indicates that the server is temporarily unable to process the request, usually due to server overload or maintenance.

It should be noted that different servers and applications may return different status codes based on their own needs and configurations. Therefore, in actual use, it is best to check the documentation of the server or application for accurate information.