Yes. 4xx codes are client errors: The request contains a mistake or can't be fulfilled as sent.

4xx · Client error

HTTP 408 Request Timeout

The server gave up waiting for the request. Retrying is usually fine.

Example response

HTTP

HTTP/1.1 408 Request Timeout
Content-Type: application/json; charset=utf-8

{ "error": "Request Timeout" }

Look up the headers shown here in the HTTP headers reference.

What does HTTP 408 mean?: Request Timeout. The server gave up waiting for the request. Retrying is usually fine.
Is 408 an error?: Yes. 4xx codes are client errors: The request contains a mistake or can't be fulfilled as sent.