HTTP Status Codes

Introduction to HTTP Status Codes #

Status Codes A feature that informs the client about the processing status of the request it sent in the response.

• 1xx (Informational) : Request received and being processed
• 2xx (Successful) : Request successfully processed
• 3xx (Redirection) : Further action is required to complete the request
• 4xx (Client Error) : Client error, server cannot fulfill the request due to malformed syntax, etc.
• 5xx (Server Error) : Server error, server failed to fulfill a valid request

What if an unknown status code appears?

• If the server returns a status code that the client does not recognize?
• The client interprets and processes it as the higher-level status code.
• No need to change the client even if new status codes are added in the future.
• Example)
  • 299 ??? -> 2xx(Successful)
  • 451 ??? -> 4xx(Client Error)
  • 599 ??? -> 5xx(Server Error)

1xx (Informational) #

Request received and being processed

• Rarely used, so omitted