When a visitor visits a web page, the visitor’s browser makes a request to the server where the page is located. When the browser receives and displays a web page, the server where the web page resides returns a Server header containing an HTTP status code in response to the browser’s request.
The HTTP Status Code is HTTP Status Code.
The following are common HTTP status codes:
200 – Request successful
301 – Resources (web pages, etc.) are permanently moved to another URL
404 – The requested resource (web page, etc.) does not exist
500 — Internal server error
HTTP status code classification
The HTTP status code consists of three decimal digits. The first decimal digit defines the type of the status code, and the second two digits do not classify. HTTP status codes are classified into five types:
HTTP status code classification
Classification description
1** message, the server received the request, the requester to continue to perform the operation
2** Succeeded. The operation is successfully received and processed
3** redirect, further action is required to complete the request
4** Client error, request contains syntax error or request cannot be completed
5** Server error. The server encountered an error while processing the request
HTTP status code list:
HTTP status code list
Status code English name Chinese description
100 Continue. The client should continue with its request
101 Switching Protocols Switching protocol. The server switches protocols based on client requests. You can only switch to a more advanced protocol, for example, the new version of HTTP
200 The OK request succeeded. Typically used for GET and POST requests
201 Created Created. The new resource was successfully requested and created
202 Accepted. The request has been accepted, but processing is not complete
Our Authoritative Information is Authoritative. The request succeeded. The meta information returned is not the original server, but a copy
204 No Content No Content. The server processed successfully, but did not return content. You can ensure that the browser continues to display the current document without updating the web page
205 Reset Content Resets the Content. The server is successful, and the user end (for example, browser) should reset the document view. Use this return code to clear the browser’s form field
206 Partial Content The server successfully processed some of the GET requests
300 Multiple Choices. The requested resource can include multiple locations, and a list of resource characteristics and addresses can be returned for user terminal (e.g., browser) selection
301 Moved Permanently Moved Permanently. The requested resource has been permanently moved to the new URI, the return message will include the new URI, and the browser will automatically redirect to the new URI. Any future new requests should be replaced with a new URI
302 Found temporary movement. Similar to 301. But resources are moved only temporarily. The client should continue to use the original URI
303 See Other View Other IP addresses. Similar to 301. Use GET and POST requests to view
304 Not Modified. The requested resource is not modified, and the server does not return any resources when it returns this status code. Clients typically cache accessed resources by providing a header indicating that the client wants to return only resources that have been modified after a specified date
305 Use Proxy Uses Proxy. The requested resource must be accessed through a proxy
306 Unused INDICATES the Unused HTTP status code
307 Temporary Redirect Temporary redirection. Similar to 302. Use GET to request redirection
400 Bad Request The syntax of the client Request is incorrect and cannot be understood by the server
401 Unauthorized Requests require user authentication
402 Payment Required for future use
403 Forbidden The server understands the request from the client but rejects the request
404 Not Found The server could Not find the resource (web page) requested by the client. With this code, a web designer can set up a personalized page that says “the resource you requested could not be found.
405 Method Not Allowed The Method in the client request is prohibited
406 Not Acceptable The server was unable to complete the request based on the content nature of the client request
407 Proxy Authentication Required The request requires the identity of the Proxy, similar to that of the 401, but the requester should use the Proxy for authorization
408 Request time-out The server waits for the Request sent by the client for a long Time and times out
409 Conflict server may return this code when it completes a client PUT request. A Conflict occurred when the server processed the request
410 Gone The resource requested by the client does not exist. 410 differs from 404 in that if a resource previously had a 410 code that is now permanently deleted, the site designer can specify a new location for the resource through the 301 code
411 Length Required The server cannot process requests without Content-Length sent by clients
412 Precondition Failed The client’s request information
413 Request Entity Too Large The server rejects the Request because the requested Entity is Too Large. To prevent continuous requests from clients, the server may close the connection. If the server is temporarily unable to process it, a retry-after response is included
414 Request-URI Too Large The URI of the Request is Too long (usually the URL), and the server cannot process it
415 Unsupported Media Type The server cannot process the Media format attached to the request
416 Requested range not satisfiable Client request range invalid
417 Expectation Failed The server cannot meet Expect’s request header information
500 Internal Server Error Indicates an Internal Server Error. The request cannot be completed
501 Not Implemented The request was Not supported by the server
502 Bad Gateway The server working as a Gateway or proxy received an invalid response from the remote server when attempting to execute the request
503 Service Unavailable The server cannot process requests from clients temporarily due to overload or system maintenance. The length of the delay can be included in the server’s retry-after header
504 Gateway time-out The server acting as a Gateway or proxy fails to obtain requests from the remote server in a timely manner
505 HTTP Version Not Supported The server does not support the HTTP Version