A status code is a description of the server’s response to a client request. By using the status code, the user can know whether the server processed the request normally or if an error occurred. If the record is not considerate, thank you for your correction!

Status code format

3 digit number + reason phrase e.g. 200 OK

Category of the status code

Common status codes

Success class status code
  • 200 OK
    • Indicates that the client request is received by the server
    • In the response message, the information returned with the status code changes depending on the HTTP method. For example, when using the GET method, the corresponding request entity is returned as a response, whereas the HEAD method only returns the header, not the body of the entity
  • 204 No Content
    • Indicates that the server receives the client request, but no resource is returned
  • 206 Partal Content
    • Indicates that the client made a scope request and the server successfully responded to the specified portion of entity content
Redirection status code
  • 301 Moved Permanently
    • The specified URI resource has been permanently changed
  • 302 Found
    • Specifies that the URI resource is temporarily saved to another location and that the user is expected to access it using the new URI
  • 303 See Other
    • Specifies that the URI resource is temporarily saved to another location, expecting the user to access the new URI using the GET method

  • 304 Not Modified
    • Indicates that the client sends a conditional request, but the server resource does not meet the condition
    • Although 304 is in the redirection category, it has nothing to do with redirection
  • 307 Temporary Redirect
    • Specifies that the URI resource is temporarily saved to another location and that the user is expected to access it using the new URI
    • Unlike 302 status codes, 307 obeys browser standards and does not change from POST to GET. Although 302 is also prohibited, it is not followed in practice
Client error
  • 400 Bad Request
    • A syntax error exists in the request packet, and the browser treats the status code as 200 OK
  • 401 Unauthorized
    • Indicates the information that requires HTTP authentication (BASIC authentication and DIGEST authentication). If the request has been made once before, the verification fails. The 401 status code must contain a www-authenticate header to challenge the user’s information
  • 403 Forbidden
    • Access to the specified URi was denied
  • 404 Not Found
    • There is no resource on the server with the specified URI
Server error
  • 500 Internal Server Error
    • Server internal error
  • 503 Service Unavailable
    • Indicates that the server is maintained internally