HTTP status codes and their meanings

The HTTP status code (HTTP status code) is a 3-bit numeric code that represents the HTTP response status of a Web server.

1 The Beginning (information Class) means to receive the request and continue processing
100 the customer must continue to issue the request
101 client requires server to convert HTTP protocol version on request

2 The beginning (successful request) indicates that the requested status code was successfully processed.

200 (successful) the server has successfully processed the request. Typically, this indicates that the server has 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 returned information 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 content) the server successfully processed a partial GET request.

3 The beginning (the request is redirected) indicates that to complete the request, further action is required. Typically, these status codes are used for redirection.

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

4 Start (Request error) These status codes indicate that the request could be wrong, preventing the server from processing.

400 (Error request) The server does not understand the syntax of the request.
401 (not authorized) request authentication. The server may return this response for Web pages that need to log on.
403 (Prohibited) the server refused the request.

403.1 Prohibit access: Prohibit executable access
403.2 No access: no Read access
403.3 No access: no Write access
403.4 No access: Require SSL
403.5 No access: SSL 128 required

403.6 No access: IP address denied
403.7 No access: Require a client certificate
403.8 Prohibit access: Prohibit site access
403.9 No access: too many connected users
403.10 No access: Invalid configuration
403.11 No access: Password change
403.12 No access: The mapper denies access
403.13 No access: Client certificate has been revoked
403.15 No access: Too many Client access licenses
403.16 Prohibit access: Client certificate is not trustworthy or invalid
403.17 No access: Customer certificate has expired or has not yet entered into force
404 (Not found) the server could not find the requested Web page.
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 (proxy authorization required) This status code is similar to 401 (not authorized), but the specified requester should authorize the use of the agent.
408 (Request timed out) timeout occurs when the server waits for a request.
409 (conflicting) the server encountered a conflict while completing the request. The server must contain information about the conflict in the response.
410 (Deleted) If the requested resource has been permanently deleted, the server returns this response.
411 (requires a valid length) the server does not accept requests that do not contain a valid content Length header field.
412 (Prerequisites not met) the server did not meet one of the prerequisites that the requester set in the request.
413 (Request entity too Large) the server was unable to process the request because the request entity was too large to handle 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 (Request range does not meet the requirements) if the page cannot provide the requested scope, the server returns this status code.
417 (expectations not met) the server did not meet the requirements for the "expected" Request header field.

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

500 (server internal error) the server encountered an error and could not complete the request.

500.11 Server shutdown
500.12 Application reboot
500.13 server is too busy
500.14 Application is invalid
500.15 not allowed to request Global.asa

500.100 Internal Server error-ASP error
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 received 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). Usually, this is only a temporary state.
504 (Gateway Timeout) The server acts as a gateway or proxy, but does not receive requests from upstream servers in a timely manner.
505 (HTTP version is not supported) the server does not support the HTTP protocol version used in the request.

Reproduced from: https://blog.csdn.net/dufufd/article/details/53112184

Https://www.cnblogs.com/jianying/p/7992622.html