Standard HTTP status code

Number	Description
100	Continue
101	Switching protocols
200	OK
201	Created
202	Accepted
203	Non-authoritative information
204	NO content
205	Reset content
206	Partial content
300	Multiple Choices
301	Moved permanently
302	Found
303	See other
304	Not modified
305	Use proxy
307	Temporary redirect
400	Bad request
401	Unauthorized
402	Payment required
403	Forbidden
404	Not found
405	Method not allowed
406	Not acceptable
407	Proxy authentication required
408	Request timeout
409	Conflict
410	Gone
411	Length required
412	Precondition failed
413	Request Entity too large
414	Request-URI Too Long
415	Unsupported media type
416	Requested range not suitable
417	Expectation failed
500	Internal Server Error
501	Not Implemented
502	Bad Gateway
503	Service unavailable
504	Gateway timeout
505	HTTP Version Not Supported

 

 

 

 

1.1 message 1xx (informational 1xx)
This type of status code is used to indicate a temporary response. A temporary response is composed of status-line and optional titles, and is terminated by a blank line. No 1xx status code is defined in HTTP/1.0, so they are not legal responses to HTTP/1.0 requests. In fact, they are mainly used for lab purposes, which is beyond the scope of this document.

1.2 success 2XX (successful 2XX)
Indicates that the client request is successfully received, understood, and accepted.
200 OK
The request is successful. The response information depends on the method used by the request, as follows:
The resource to be requested by get has been placed in the response entity.
The head has no entity, and only the title information is included in the response.
Post object (description or result containing the operation ).
201 created
After the request is completed, the new resource is created. The URI of the newly created resource can be obtained in the response object. The original server should create the resource before sending the status code. If this operation cannot be completed immediately, the server must give a prompt in the response body when the resource is available. Otherwise, the server should respond to 202 (acceptable ).
In the method defined in this article, only post can create resources.
202 accepted
The request is accepted, but the processing has not been completed. The request may not be completed and may be interrupted at any time. In this case, there is no way to resend the status code in an asynchronous operation.
202 there is no obligation to respond. The purpose is to allow the server to respond to requests from other processes (such as running once a day, based on the batch processing process ).
The entities returned in some responses include the status indication of the current request, the status monitor pointer, or the user's evaluation information on whether the request can be implemented.
204 NO content
The server has implemented the request, but no new information is returned. If the customer is a user agent, do not update the document view for this. This response mainly aims to input script statements and perform other operations without affecting the activation of the document view by the user agent. This response may also contain new meta information in the form of entity titles, which can be used by the documents in the active view of the current user agent.

1.3 redirection (redirection 3xx)
This type of Status Code indicates that the user agent needs to perform further operations to complete the request. These operations can be implemented by the user agent only when the followed request is get or head, instead of interacting with the user. The user agent never performs more than five redirection operations on the request, which may lead to an infinite loop.
300 multiple choices
This status code is not directly used by HTTP/1.0 applications, but serves as the default explanation for 3xx type responses. Multiple available requested resources exist.
Unless it is a head request, the response entity must include the character list and location information of these resources. The user or user agent determines which one is the most suitable.
If the server has a preferred choice, it should store the corresponding URL Information in the location field, and the user agent will automatically redirect according to the value of this field.
301 moved permanently
A permanent URL will be allocated to the requested resource, so that you can access this resource through this URL in the future. The client with the link editing function will automatically update the request URI based on the new link returned by the server as much as possible. The new URL must be specified by the location field in the response. Unless it is a head request, the entity body to be responded must include a brief description of the new URL hyperlink.
If the post method is used to send a request, the 301 response status code is received. In this case, unless confirmed by the user, the user agent does not need to redirect the request automatically, because this will change the environment in which the request has been sent.
Note: When the POST request is automatically redirected after the 301 status code is received, some existing user proxies mistakenly Change it to get requests.
302 moved temporarily
The requested resource is temporarily saved in a different URL. Because redirection is sometimes changed, the client should continue to use the request URI to send future requests. The new URL must be specified by the location field in the response. Unless it is a head request, the entity body to be responded must include a brief description of the new URL hyperlink.
If the post method is used to send a request, the 302 response status code is received. In this case, unless confirmed by the user, the user agent does not need to redirect the request automatically, because this will change the environment in which the request has been sent.
Note: When the POST request is automatically redirected after the 302 status code is received, some existing user proxies mistakenly Change it to get requests.
304 not modified
If the client successfully executes the conditional GET request and the corresponding file has not been updated since the date specified by the IF-modified-since domain, the server should respond to this status code, instead of sending the entity body to the client. The Response Header domain should only contain some relevant information, such as the cache manager and the modification irrelevant to the last-modified Date of the entity. Examples of related subject domains include date, server, and expiration time. Whenever the Domain value given in the 304 response changes, the cache should update the cached entity.

1.4 client error 4xx
The status code of the 4xx class indicates that an error occurs on the client. If the request has not been completed when the client receives the 4xx code, it should immediately terminate sending data to the server. In addition to responding to head requests, the server must include an explanation of the error status in the response entity, whether the error is temporary or permanent. These Status Codes apply to any request method.
Note: If the client is sending data, the TCP implementation of the server should be careful to ensure that the client receives the response packet before closing the input connection. If the client still sends data to the server after it is disabled, the server will send a reset packet to the client to clear the input buffer that has not been processed by the client, so as to terminate the reading and interpreting activities of the HTTP application.
400 invalid request)
If the request syntax is incorrect, the server cannot understand it. The client should not repeatedly send the request to the server before making changes to the request.
401 unauthorized)
User authorization is required for the request. The WWW-Authenticate header field (section 10.16) in the response should prompt the user to request resources in an authorized manner. The client should use the appropriate authorization title domain (section 10.2) to repeat the request. If the request contains the authorization trust information, the 401 response indicates that the authorization is denied. If the user agent returns Status Code 401 after multiple attempts, the user should check the response entity because the entity contains some dynamic information. HTTP access authorization will be explained in section 11.
403 Forbidden)
The server understands the request, but rejects the request. Authorization does not help. The client should stop sending this request repeatedly. If the head request method is not used and the server is willing to publish the reason for the request being not implemented, the server will write the reason for rejection in the response entity. This status code is generally used when the server does not want to disclose the details of the request being rejected or no other response is available.
404 not found)
The server does not find the resource that matches the request URI. The 404 Status Code does not indicate whether the status is temporary or permanent. If the server does not want to provide this information to the client, it also responds to the 403 (Forbidden) status code.

1.5 server error 5xx
The status code starting with '5' indicates that the server finds an error and cannot continue to execute the request. If the client has not completed the request when receiving the 5xx status code, it should immediately stop sending data to the server. In addition to responding to head requests, the server should include an explanation of the error situation in its response entity and specify that it is temporary and permanent.
This type of response code does not have a title field and can be applied to any request method.
500 Internal Server Error)
The server failed to respond to the request due to an unexpected situation.
501 not implemented (not implemented)
The server cannot provide support for the functions required in the request. If the server cannot identify the request method, it will respond to this status code, which means it cannot respond to any resource requested by the request.
502 illegal Gateway)
The server acting as the gateway or proxy receives an invalid response from the upstream (upstream) server that sends the request.
503 service unavailable)
The server cannot process the request currently. This is generally caused by temporary server overload or maintenance. This status code implies that the situation is temporary and requires some delay.
Note: The 503 Status Code does not imply that the server must return this status code when it is overloaded. Some servers may want to use simple processing during overload, that is, disconnect the connection.

Summary of IIS error codes
400 the request cannot be parsed.
401.1 unauthorized: access is denied due to invalid creden.
401.2 unauthorized access: access is denied due to server configuration preference to use alternative authentication methods.
401.3 unauthorized: access to requested resources is denied due to ACL settings.
401.4 unauthorized: the filter installed on the Web server fails to be authorized.
401.5 unauthorized: The ISAPI/cgi application fails to be authorized.
401.7 unauthorized: access is denied due to the URL Authorization Policy on the Web server.
403 Access prohibited: access is denied.
403.1 Access prohibited: Access denied.
403.2 Access prohibited: Read access is denied.
403.3 Access prohibited: Write access is denied.
403.4 forbidden access: use SSL to view the resource.
403.5 forbidden access: use SSL 128 to view the resource.
403.6 Access prohibited: the client's IP address is denied.
403.7 Access prohibited: An ssl client certificate is required.
403.8 Access prohibited: the client's DNS name is denied.
403.9 Access prohibited: too many clients attempt to connect to the web server.
403.10 Access prohibited: the Web server is configured to reject access requests.
403.11 Access prohibited: the password has been changed.
403.12 Access prohibited: the server certificate er rejects access to the client certificate.
403.13 Access prohibited: the client certificate has been revoked on the Web server.
403.14 forbidden access: the directory list has been denied on the Web server.
403.15 Access prohibited: the Web server has exceeded the Client Access License limit.
403.16 Access prohibited: the client certificate format is incorrect or is not trusted by the Web server.
403.17 Access prohibited: the client certificate has expired or has not yet taken effect.
403.18 Access prohibited: the requested URL cannot be executed in the current application pool.
403.19 Access prohibited: CGI cannot be executed for the client in the application pool.
403.20 Access prohibited: Passport Logon Failed.
404 the file or directory cannot be found.
404.1 file or directory not found: the website cannot be accessed on the requested port.
Note that the 404.1 error only appears on a computer with multiple IP addresses. If a client request is received on a specific IP Address/Port Combination and the IP address is not configured to listen on the specific port, IIS returns the 404.1 HTTP Error. For example, if a computer has two IP addresses and only one of them is configured to listen on port 80, any request received from port 80 from another IP address will cause IIS to return the 404.1 error. This error should be set only at this service level, because it is returned to the client only when multiple IP addresses are used on the server.
404.2 files or directories cannot be found: the request is forbidden by the locking policy.
404.3 files or directories cannot be found: the mime ing policy disables this request.
405 the HTTP action used to access the page is not permitted.
406 the client browser does not accept the MIME type of the requested page.
407 the Web server requires initial proxy verification.
410 the file has been deleted.
412 the prerequisites set by the client fail to be evaluated on the Web server.
414 the request URL is too large to be accepted on the Web server.
500 internal server error.
500.11 server error: the application on the Web server is being closed.
500.12 server error: the application on the Web server is restarting.
500.13 server error: the Web server is too busy.
500.14 server error: Invalid application configuration on the server.
500.15 server error: you cannot directly request global. Asa.
500.16 server error: Invalid UNC authorization credential.
500.17 server error: the URL authorized storage cannot be found.
500.18 server error: the URL authorized storage cannot be opened.
500.19 server error: the file data is incorrectly configured in the configuration database.
500.20 server error: the URL Authorization domain cannot be found.
500.100 internal server error: ASP error.
501 the configuration specified by the title value is not executed.
502 when the web server acts as a gateway or proxy server, it receives an invalid response.