HTTP status code
When a viewer visits a web page, the viewer’s browser makes a request to the server where the web page is located. Before the browser receives and displays the web page, the server where the web page is located will return an information header (server header) containing the HTTP status code in response to the browser’s request.
The English name of HTTP status code is HTTP Status Code.
Here are common HTTP status codes:
200-request succeeded
301-Resources (web pages, etc.) are permanently transferred to other 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 of which defines the type of status code. Responses are divided into five categories: information response (100mur199), successful response (200mur299), redirection (300mur399), client error (400mur499) and server error (500mur599):
classification |
Classification description |
|---|---|
1 |
Message, the server receives the request and requires the requestor to continue to perform the operation |
2 |
Successful, the operation is received and processed successfully |
3 |
Redirect, further action is required to complete the request |
4 |
Client error, request containing syntax error or unable to complete request |
5 |
Server error, an error occurred while the server was processing the request |
List of HTTP status codes:
Status code |
English name of status code |
Chinese description |
|---|---|---|
100 |
Continue |
Go ahead. The client should continue its request |
101 |
Switching Protocols |
Switch protocols. The server switches the protocol according to the request of the client. You can only switch to a more advanced protocol, for example, to a new version of HTTP |
200 |
OK |
The request was successful. Commonly used for GET and POST requests |
201 |
Created |
Created. Successfully requested and created a new resource |
202 |
Accepted |
Accepted. The request has been accepted but the processing has not been completed |
203 |
Non-Authoritative Information |
Unauthorized information. The request was successful. But the returned meta information is not on the original server, but on a copy. |
204 |
No Content |
No content. The server successfully processed but did not return content. If the web page is not updated, ensure that the browser continues to display the current document |
205 |
Reset Content |
Reset the content. The server is processed successfully, and the user terminal (for example, browser) should reset the document view. The form field of the browser can be cleared by this return code |
206 |
Partial Content |
Part of the content. The server successfully processed some GET requests |
300 |
Multiple Choices |
A variety of options. The requested resource may include multiple locations, which can return a list of resource characteristics and addresses for user terminal (e. G. browser) selection |
301 |
Moved Permanently |
Move forever. The requested resource has been permanently moved to the new URI, the returned information will include the new URI, and the browser will be automatically directed to the new URI. Any new requests in the future should be replaced by a new URI |
302 |
Found |
Temporary movement. Similar to 301. But resources are only temporarily moved. The client should continue to use the original URI |
303 |
See Other |
Check for other addresses. Similar to 301. Use GET and POST to request view |
304 |
Not Modified |
Not modified. The requested resource has not been modified, and when the server returns this status code, no resource will be returned. The client usually caches the accessed resources, indicating that the client wants to return only those resources that have been modified after the specified date by providing a header information |
305 |
Use Proxy |
Use a proxy. The requested resource must be accessed through an agent |
306 |
Unused |
Obsolete HTTP status code |
307 |
Temporary Redirect |
Temporary redirection. Similar to 302. Request redirection using GET |
400 |
Bad Request |
The syntax of the client request is incorrect and the server cannot understand it. |
401 |
Unauthorized |
The request requires the user’s identity authentication |
402 |
Payment Required |
Keep, use in the future |
403 |
Forbidden |
The server understands the request of the requesting client, but refuses to execute the request |
404 |
Not Found |
The server cannot find the resource (web page) according to the client’s request. Through this code, the website designer can set up a personality page that the resource you requested cannot be found. |
405 |
Method Not Allowed |
Methods in client requests are prohibited |
406 |
Not Acceptable |
The server cannot complete the request based on the content characteristics of the client request |
407 |
Proxy Authentication Required |
The request requires the authentication of the agent, similar to 401, but the requestor should use the agent for authorization |
408 |
Request Time-out |
The server waited too long for the request sent by the client, and timed out |
409 |
Conflict |
This code may be returned when the server completes the client’s PUT request, and a conflict occurs when the server processes the request |
410 |
Gone |
The resource requested by the client no longer exists. 410 is different from404, if the resource has been permanently deleted and can use 410 code, thewebsite designer can specify the new location of the resource through 301 code. |
411 |
Length Required |
The server cannot process the request information sent by the client withoutContent-Length |
412 |
Precondition Failed |
Prerequisite error for client request information |
413 |
Request Entity Too Large |
The request was rejected because the requested entity was too large for the server to process. To prevent continuous requests from the client, the server may close the connection. If only the server cannot process it temporarily, it will contain a Retry-After response message. |
414 |
Request-URI Too Large |
The requested URI is too long (the URI is usually the URL) and the server cannot process it |
415 |
Unsupported Media Type |
The server cannot process the media format that came with the request |
416 |
Requested range not satisfiable |
The scope of the client request is invalid |
417 |
Expectation Failed |
The server cannot satisfy the request header information of Expect |
500 |
Internal Server Error |
Internal error in the server, unable to complete the request |
501 |
Not Implemented |
The server does not support the requested function and cannot complete the request |
502 |
Bad Gateway |
When the server working as a gateway or agent tried to execute the request, it received an invalid response from the remote server |
503 |
Service Unavailable |
The server is temporarily unable to process client requests due to overloading or system maintenance. The length of the delay can be included in the server’s Retry-After header information |
504 |
Gateway Time-out |
A server that acts as a gateway or agent that fails to obtain requests from a remote server in a timely manner |
505 |
HTTP Version not supported |
The server does not support the version of the requested HTTP protocol and cannot complete the processing |