Common HTTP Status Codes (HTTP state code)

as a program developer, you should know the meaning of the HTTP status returned by some servers, and only make sure that the status code one by one is clear and that the various problems encountered in the work can be handled with ease. So let's take a look at the more common HTTP status codes now! 2** Opening (successful request) indicates that the request's status code was successfully processed.

200 (success) The server has successfully processed the request. Typically, this indicates that the server provided the requested Web page.
201 (created) The request was successful and the server created a new resource.
202 (accepted) the server has accepted the request but has not yet processed it.
203 (non-authoritative information) the server has successfully processed the request, but the information returned may be from another source.
204 (no content) the server successfully processed the request, but did not return any content.
205 (reset content) the server successfully processed the request, but did not return any content.
206 (partial) The server successfully processed a partial GET request.

3** Opening (request redirection) indicates that a request is to be completed and further action is required. Typically, these status codes are used for redirection.

300 (multiple options) for requests, the server can perform a variety of operations. The server can select an action based on the requestor (user agent) or provide a list of actions for the requestor to select.
301 (permanently moved) The requested page has been permanently moved to a new location. When the server returns this response (a response to a GET or HEAD request), the requestor is automatically forwarded to the new location.
302 (Temporary move) The server is currently responding to requests from a Web page in a different location, but the requestor should continue to use the original location for future requests.
303 (View other locations) The server returns this code when the requestor should use a separate GET request for the different locations to retrieve the response.
304 (not modified) The requested webpage has not been modified since the last request. When the server returns this response, the Web page content is not returned.
305 (using a proxy) the requestor can only use the proxy to access the requested Web page. If the server returns this response, it also indicates that the requestor should use the proxy.
307 (Temporary redirect) The server is currently responding to requests from a Web page in a different location, but the requestor should continue to use the original location for future requests.

4** Start (Request error) These status codes indicate that the request may be faulty and hinder the processing of the server.

400 (Error request) The server does not understand the syntax of the request.
401 (unauthorized) request authentication is required. The server may return this response for pages that need to log on.
403 (Forbidden) The server rejects the request.
404 (Not Found) The requested Web page was not found by the server.
405 (method Disabled) Disables the method specified in the request.
406 (not accepted) cannot use the requested content attribute to respond to the requested Web page.
407 (requires proxy authorization) This status code is similar to 401 (unauthorized), but specifies that the requestor should authorize the use of the proxy.
408 (Request timed out) A timeout occurred while the server was waiting for a request.
409 (conflict) The server has a conflict when it finishes the request. The server must include information about the conflict in the response.
410 (Deleted) If the requested resource has been permanently deleted, the server returns this response.
411 (requires valid length) The server does not accept requests that do not contain a valid Content-Length header field.
412 (precondition not met) the server does not meet one of the prerequisites set by the requestor in the request.
413 (Request entity too Large) The server cannot process the request because the request entity is too large to exceed the processing power of the server.
414 (The requested URI is too long) The requested URI (usually the URL) is too long for the server to process.
415 (Unsupported media type) The requested format is not supported by the requested page.
416 (The request scope does not meet the requirements) if the page cannot provide the requested scope, the server returns this status code.
417 (unmet expectations) the server does not meet the requirements for the expected Request header field.

5** Start (server error) These status codes indicate that the server has an internal error while trying to process the request. These errors may be the error of the server itself, not the request.

500 (server internal error) the server encountered an error and could not complete the request.
501 (not yet implemented) the server does not have the capability to complete the request. For example, this code may be returned when the server does not recognize the request method.
502 (Error Gateway) The server receives an invalid response from the upstream server as a gateway or proxy.
503 (Service Unavailable) the server is not currently available (due to overloading or downtime maintenance). Typically, this is only a temporary state.
504 (Gateway Timeout) The server acts as a gateway or proxy, but does not receive requests from the upstream server in a timely manner.
505 (HTTP version not supported) the HTTP protocol version used in the request is not supported by the server.

1xx-Informational Tips

These status codes represent a temporary response. The client should be prepared to receive one or more 1xx responses before receiving a regular response.

· 100-continue the initial request has been accepted, the customer should continue to send the remainder of the request. (HTTP 1.1 new)
· 101-switching Protocols Server translates the client's request to another protocol (HTTP 1.1 new)

2XX-Success
This type of status code indicates that the server successfully accepted the client request.

· 200-ok Everything is OK, the answer document for Get and post requests is followed.
· The 201-created server has created the document, and the location header gives its URL.
· 202-accepted has accepted the request, but the processing has not been completed.
· The 203-non-authoritative information document has returned normally, but some of the answer headers may be incorrect because a copy of the document is being used, non-authoritative (HTTP 1.1 new).
· 204-no Content does not have a new document, the browser should continue to display the original document. This status code is useful if the user refreshes the page on a regular basis and the servlet can determine that the user's document is new enough.
· 205-reset content is not new, but the browser should reset what it displays. Used to force the browser to clear the form input (HTTP 1.1 new).
· The 206-partial Content client sent a GET request with a range header (block request) and the server completed it (HTTP 1.1 new).

3xx-redirect
The client browser must take more action to implement the request. For example, the browser might have to request a different page on the server, or repeat the request through a proxy server.

· 300-multiple Choices Customer-requested documents can be found in multiple locations that are listed in the returned document. If the server wants to make a preference, it should be indicated in the location answer header.
· 301-moved permanently The document requested by the customer elsewhere, the new URL is given in the location header, and the browser should automatically access the new URL.
· 302-found is similar to 301, but the new URL should be treated as a temporary replacement, not a permanent. Note that the corresponding status information in HTTP1.0 is "Moved temporatily". When the status code appears, the browser can

To automatically access the new URL, so it is a useful status code. Note that this status code can sometimes be used with 301 substitutions. For example, if the browser mistakenly requests Http://host/~user (the trailing slash is missing)

, some servers return 301, and some return 302. Strictly speaking, we can only assume that the browser will automatically redirect only if the original request is get. See 307.
· 303-see other is similar to 301/302, except that if the original request is post,location, the redirect target document specified by the header should be fetched via get (HTTP 1.1 new).
· The 304-not Modified client has a buffered document and issues a conditional request (typically providing a if-modified-since header indicating that the customer only wants to update the document than the specified date). The server tells the customer that the original buffered

The document can also continue to be used.
· 305-use Proxy The document requested by the client should be extracted via the proxy server indicated by the location header (HTTP 1.1 is new).
· 307-temporary Redirect and 302 (Found) are the same. Many browsers incorrectly respond to a 302 response for redirection, even if the original request is post, even though it can actually only be re-answered when the POST request is 303

Directional. For this reason, HTTP 1.1 has been added in 307 to allow for more cleanup of the region in several status codes: When a 303 response occurs, the browser can follow the redirected get and post requests, and if the 307 answer, the browser can only follow

The redirect to the GET request. (HTTP 1.1 new)

4xx-Client Error
An error occurred and the client appears to be having problems. For example, a client requests a page that does not exist, and the client does not provide valid authentication information.

· 400-bad request syntax error occurred.
· 401-unauthorized access was denied and the customer attempted to access a password-protected page without authorization. A www-authenticate header is included in the answer, and the browser displays the user name/Password dialog box and then fills in the

After the authorization, the request is made again. IIS defines a number of different 401 errors, which indicate a more specific cause of the error. These specific error codes are displayed in the browser, but are not displayed in the IIS log:
· 401.1-Login failed.
· 401.2-The server configuration caused the login to fail.
· 401.3-not authorized due to ACL restrictions on resources.
· 401.4-Filter Authorization failed.
· 401.5-ISAPI/CGI application authorization failed.
· 401.7– access is denied by the URL authorization policy on the WEB server. This error code is specific to IIS 6.0.
· 403-forbidden resource is not available. The server understands the customer's request, but refuses to process it. This is usually caused by the permissions set on the file or directory on the server. Forbidden Access: IIS defines a number of different 403 errors, which refer to the

more specific causes of the error:
• 403.1-execution access is forbidden.
• 403.2-read access is forbidden.
• 403.3-write access is forbidden.
• 403.4-Requires SSL.
• 403.5-Requires SSL 128.
The 403.6-ip address is rejected.
• 403.7-Requires a client certificate.
• 403.8-site access is denied.
• 403.9-excessive number of users.
• 403.10-Invalid configuration.
• 403.11-Password change.
• 403.12-Deny access to the mapping table.
• 403.13-The client certificate is revoked.
• 403.14-Reject directory list.
• 403.15-Client access permission exceeded.
• 403.16-client certificate is not trusted or invalid.
• 403.17-The client certificate has expired or is not yet valid.
• 403.18-The requested URL cannot be executed in the current application pool. This error code is specific to IIS 6.0.
• 403.19-CGI cannot be executed for clients in this application pool. This error code is specific to IIS 6.0.
403.20-passport Login failed. This error code is specific to IIS 6.0.
404-not Found could not find the resource at the specified location. This is also a common answer.
• 404.0-(none) – No files or directories found.
• 404.1-Unable to access the WEB site on the requested port.
the 404.2-web service extension lockout policy blocks this request.
the 404.3-mime mapping policy blocks this request.
The 405-method not allowed request method (GET, POST, HEAD, DELETE, PUT, trace, etc.) does not apply to the specified resource, and the HTTP verb used to access this page is not allowed (the method is not allowed) (HTTP 1.1

new)
406-not acceptable the specified resource has been found, However, its MIME type and the incompatibility specified by the client in the Accpet header do not accept the MIME type of the requested page (HTTP 1.1 new). The
407-proxy authentication Required requires proxy authentication, similar to 401, which indicates that the client must be authorized by the proxy server first. (HTTP 1.1 new)
408-request Timeout the customer has not made any requests during the server license wait time. Customers can repeat the same request at a later time. (HTTP 1.1 new)
409-conflict is usually related to a put request. The request cannot succeed because the request conflicts with the current state of the resource. (HTTP 1.1 new)
410-gone The requested document is no longer available, and the server does not know which address to redirect to. It differs from 404 in that returning 407 means that the document leaves the specified position permanently, and 404 means that because the unknown

Reason document is not available. (HTTP 1.1 new)
· The 411-length Required server cannot process the request unless the client sends a content-length header. (HTTP 1.1 new)
· 412-precondition Failed Some of the prerequisites specified in the request header failed (HTTP 1.1 new).
· 413–request Entity Too Large the size of the target document exceeds the size that the server is currently willing to handle. If the server thinks it can process the request later, it should provide a Retry-after header (HTTP 1.1

New).
· 414-request URI Too Long URI is too lengthy (HTTP 1.1 new).
· 415– media types not supported.
· The 416–requested range not satisfiable server does not meet the Range header specified by the customer in the request. (HTTP 1.1 New) · 417– execution failed.
· 423– a locked error.

5XX-Server Error
The server could not complete the request because it encountered an error.

The

500-internal server Error server encountered unexpected conditions and was unable to complete the client's request.
500.12-the application is busy restarting on the WEB server.
500.13-web server is too busy.
500.15-Direct request Global.asa is not allowed.
500.16–unc authorization credentials are incorrect. This error code is specific to IIS 6.0. The
500.18–url authorization store cannot be opened. This error code is specific to IIS 6.0.
500.100-Internal ASP error. The
501-not implemented server does not support the functionality required to implement the request, and the header value specifies the configuration that is not implemented. For example, a customer sends a put request that is not supported by the server. When the
502-bad the gateway or proxy, the server returned an illegal reply in order to complete the request to access the next server. Also said the Web server received an invalid response as a gateway or proxy server

。
· The 502.1-cgi application timed out.
· 502.2-CGI Application error.
· The 503-service unavailable service is unavailable and the server is unable to answer due to maintenance or overloading. For example, a servlet might return 503 if the database connection pool is full. When the server returns 503, it can provide a

Retry-after head. This error code is specific to IIS 6.0.
· When the 504-gateway Timeout network is timeout, it is used by the server acting as the proxy or gateway, indicating that the answer cannot be received from the remote server in a timely manner. (HTTP 1.1 new).
· The HTTP version indicated in the request is not supported by the 505-HTTP version not supported server. (HTTP 1.1 new)

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Common HTTP Status codes (HTTP state code)