May 27, 2021 HTTP
When a viewer visits a web page, the viewer's browser makes a request to the server on which the page is located. When the browser receives and displays the page, the server on which the page is located returns an information header with an HTTP status code in response to the browser's request.
Http Status Code is in English.
Here are the common HTTP status codes:
200 - The request was successful
301 - Resources (web pages, etc.) are permanently transferred to other URLs
404 - The requested resource (web page, etc.) does not exist
500 - Internal server error
The HTTP status code consists of three ad- and ten-digit numbers, the first of which defines the type of status code, and the last two numbers have no classification. HTTP status codes are divided into five types:
| Classification | The classification description |
|---|---|
| 1** | Information, the server receives the request and requires the requester to continue |
| 2** | Successful, the operation was successfully received and processed |
| 3** | Redirect, further action is required to complete the request |
| 4** | Client error, the request contains a syntax error or the request could not be completed |
| 5** | The server error occurred while the server was processing the request |
List of HTTP status codes:
| The status code | The English name of the status code | Chinese description |
|---|---|---|
| 100 | Continue | Go on. The client should continue its request |
| 101 | Switching Protocols | Switch protocols. T he server switches protocols based on the client's request. You can only switch to a more advanced protocol, for example, to a new version of http protocol |
| 200 | Ok | The request was successful. Generally used for GET and POST requests |
| 201 | Created | Created. A new resource was successfully requested and created |
| 202 | Accepted | Accepted. The request was accepted, but not processed |
| 203 | Non-Authoritative Information | Unauthorized information. T he request was successful. However, the meta information returned is not the original server, but a copy |
| 204 | No Content | No content. T he server processed successfully, but did not return the content. Without updating the page, make sure that the browser continues to display the current document |
| 205 | Reset Content | Reset the content. T he server processing was successful and the user terminal (e.g. browser) should reset the document view. This return code allows you to clear the browser's form field |
| 206 | Partial Content | Part of the content. The server successfully processed some GET requests |
| 300 | Multiple Choices | A variety of options. The requested resource can include multiple locations, and a list of resource characteristics and addresses can be returned for the user terminal (e.g., browser) selection |
| 301 | Moved Permanently | Permanently move. T he requested resource has been permanently moved to the new URI, and the return information will include the new URI, which the browser will automatically direct to the new URI. Any new requests in the future should be replaced by new URIs |
| 302 | Found | Temporary move. S imilar to 301. B ut resources are only temporarily moved. The client should continue to use the original URI |
| 303 | See Other | View other addresses. S imilar to 301. View using GET and POST requests |
| 304 | Not Modified | Not modified. T he requested resource has not been modified and no resources are returned when the server returns this status code. Clients typically cache accessed resources by providing a header that indicates that the client wants to return only resources modified after the specified date |
| 305 | Use Proxy | Use a proxy. The requested resource must be accessed through a proxy |
| 306 | Unused | HTTP status code that has been discarded |
| 307 | Temporary Redirect | Temporary redirection. S imilar to 302. Use GET to request redirection |
| 400 | Bad Request | The syntax requested by the client was wrong and the server could not understand it |
| 401 | Unauthorized | The request requires the user's authentication |
| 402 | Payment Required | Reserved for future use |
| 403 | Forbidden | The server understands the request from the requesting client, but refuses to execute the request |
| 404 | Not Found | The server could not find the resource (web page) at the request of the client. This code allows the site designer to set up a personality page for "Resources you requested could not be found." |
| 405 | Method Not Allowed | Methods in client requests are prohibited |
| 406 | Not Acceptable | The server was unable to complete the request based on the content characteristics requested by the client |
| 407 | Proxy Authentication Required | The request requires agent authentication, similar to 401, but the requester should use the agent for authorization |
| 408 | Request Time-out | The server waited too long for the client to send the request, which timed out |
| 409 | Conflict | It is possible that this code was returned when the server completed the client's PUT request, and there was a conflict while the server was processing the request |
| 410 | Gone | The resource requested by the client no longer exists. 410 is different from 404, if a resource has previously been permanently deleted using 410 code, site designers can specify a new location for the resource through the 301 code |
| 411 | Length Required | The server was unable to process request information sent by the client without Content-Length |
| 412 | Precondition Failed | The prerequisite for the client to request information is incorrect |
| 413 | Request Entity Too Large | The request was denied because the requested entity was too large for the server to process. T o prevent successive requests from the client, the server may shut down the connection. If only the server is temporarily unable to process it, it will contain a Retry-After response message |
| 414 | Request-URI Too Large | The requested URI is too long (URI is usually a URL) and cannot be processed by the server |
| 415 | Unsupported Media Type | The server was unable to process the media format that came with the request |
| 416 | Requested range not satisfiable | The scope requested by the client is not valid |
| 417 | Expectation Failed | The server could not satisfy The request header information for Excel |
| 500 | Internal Server Error | There was an internal error in the server and the request could not be completed |
| 501 | Not Implemented | The server does not support the functionality of the request and cannot complete the request |
| 502 | Bad Gateway | The server that acts as a gateway or proxy receives an invalid request from the remote server |
| 503 | Service Unavailable | The server was temporarily unable to process client requests due to overload or system maintenance. The length of the delay can be included in the server's Retry-After header information |
| 504 | Gateway Time-out | The server acting as a gateway or proxy did not get the request from the remote server in a timely manner |
| 505 | HTTP Version not supported | The server does not support the requested version of the HTTP protocol and cannot complete processing |