An HTTP status code is a 3-digit code used to represent the status of an HTTP response, which can be divided into five categories:

  • 100 to 199 Message response
  • 200 to 299 Successful response
  • 300 ~ 399 redirect
  • An error occurs on the 400 to 499 client
  • 500 to 599 A server error occurs

A brief introduction to some common HTTP status codes:

  • 100: The server has received the request header and the requester should continue making the request. The server returns this code to indicate that it has received the first part of the request and is waiting for the rest.
  • 200: The request was successfully processed. The presence of this status code indicates normal status.
  • 202: The server has accepted the request but has not yet processed it.
  • 300: The server can perform multiple operations on a request. The server can select an operation based on the requester or provide a list of operations for the requester to select.
  • 304: The requested resource has not been modified since the last request. When the server returns this response, it does not return the content of the resource, thus saving bandwidth and overhead.
  • 400: The server does not understand the request syntax.
  • 401: The request requires authentication. The server may return this response for a web page that requires login.
  • 403: The server rejected the request.
  • 404: The server cannot find the requested resource. For example, this code is often returned for resources that do not exist on the server.
  • 408: The server timed out while waiting for the request.
  • 500: The server encountered an error and could not complete the request.
  • 502: Server acting as gateway or proxy receives invalid response from upstream server.

Specific can consult: zh.wikipedia.org/wiki/HTTP%E…