HTTP Response Status Codes

HTTP Response Status Codes used to indicate the status / result of the HTTP request made these can be classified into Informational responses [1xx] Successful responses [2xx] Redirection messages [3xx] Client error responses [4xx] Server error responses [5xx] Informational Responses (1xx) Informational responses ( 1xx ) indicate that the request has been received and the process is continuing. They are mainly used for preliminary communication before the final response is sent. Example: Large File Upload When a client wants to send a very large file: The client first sends the request headers only, including Content-Length , Content-Type , Expect: 100-continue The server checks the request headers and performs processes like Authentication, Authorization and performs validations ensuring File size limits, Content type validity At the enn, server responds with: 100 Continue → Client can now send the file body OR a final error like 401 Unauthorized , 403 Forbidden , 413 Payload Too Large