Understand HTTP 4xx Client Error Response Codes

The 4xx family of status codes are used in HTTP responses to inform the client/browser of an error relating to the user’s request. The status codes in this family are intended to indicate a problem that should be possible to fix or remedy by the user or developer. For example, a 401 Unauthorized status code lets the user/developer know they need to provide authorization information with their request; should they re-submit the request with the additional authorization header, the request may succeed. We will explore the available client error status codes, and what additional information they convey.