Common HTTP Status Codes

HTTP Status Code is a three-digit Code used to indicate the HTTP response Status of a Web server.
You may encounter errors such as 503,404 when accessing a webpage.

Some common status codes are:

200-the server returns the webpage successfully
404-the requested webpage does not exist
503-service unavailable
Detailed breakdown:

1xx (temporary response)
Status Code indicating a temporary response and requiring the requester to continue the operation.

Code Description
100 The Continue (Continue) requestor shall Continue to make the request. The server returns this code, indicating that the first part of the request has been received and is waiting for the remaining part.
101 Switching Protocols (Switching protocol) the requester has requested the server Switching protocol. The server has confirmed and is ready to switch.

2xx (successful)
Indicates that the request status code is successfully processed.

Code Description
200 OK (successful) the server has successfully processed the request. Generally, this indicates that the server provides the requested webpage.
201 Created (Created) request is successful and the server creates a new resource.
202 The Accepted (Accepted) server has Accepted the request but has not yet processed it.
203 the Non-Authoritative Information server has successfully processed the request, but the returned Information may come from another source.
204 the No Content server successfully processes the request, but does not return any Content.
205 the Reset Content server successfully processes the request but does not return any Content.
206 the Partial Content server successfully processes some GET requests.

3xx (redirection)
Indicates that further operations are required to complete the request. These status codes are usually used for redirection.

Code Description
300 Multiple Choices (Multiple options) for requests, the server can perform Multiple operations. The server selects an operation based on the user agent or provides an operation list for the user agent to select.
301 the webpage of the Moved Permanently (permanent mobile) request has been Permanently Moved to a new location. When the server returns this response (response to a GET or HEAD request), it automatically redirects the requester to a new location.
302 currently, the Found (temporary mobile) server responds to requests from different locations, but the requester should continue to use the original location for subsequent requests.
303 the server returns this code when the See Other (view Other locations) requestor uses a separate GET request for different locations to retrieve the response.
304 Not Modified (Not Modified) the requested webpage has Not been Modified since the last request. When the server returns this response, no webpage content is returned.
305 Use Proxy (using Proxy) the requester can only Use Proxy to access the requested webpage. If the server returns this response, it also indicates that the requester should use a proxy.
307 the Temporary Redirect (Temporary redirection) server currently responds to requests from webpages in different locations, but the requester should continue to use the original location for subsequent requests.

4xx (request error)
These status codes indicate that the request may fail and impede server processing.

Code Description
400 the Bad Request server does not understand the Request syntax.
401 Unauthorized (Unauthorized) requests require authentication. The server may return this response for webpages that require logon.
403 Forbidden (Forbidden) The server rejects the request.
404 Not Found (Not Found) The server cannot find the requested webpage.
405 Method Not Allowed (Method disabled) disables the Method specified in the request.
406 Not Acceptable (Not accepted) cannot use the Content features of the request to respond to the requested webpage.
407 Proxy Authentication Required (requires Proxy authorization) this status code is similar to 401 (unauthorized), but the specified requester should authorize the use of the Proxy.
408 Request Timeout occurs when the server waits for the Request.
409 a Conflict occurs when the Conflict server completes the request. The server must contain conflict information in the response.
410 Gone (Deleted) If the requested resource has been permanently deleted, the server returns this response.
411 Length Required (valid Length Required) the server does not accept requests that do not contain valid Content Length header fields.
412 Precondition Failed (not meeting the prerequisites) the server does not meet one of the prerequisites set by the requester in the request.
413 Request Entity Too Large (the Request Entity is Too Large) The server cannot process the Request because the Request Entity is Too Large and exceeds the server's processing capability.
414 Request-URI Too Long (the requested URI is Too Long) The Request URI (usually the URL) is Too Long and cannot be processed by the server.
415 the format of the Unsupported Media Type (Unsupported Media Type) request is not supported by the request page.
416 Requested Range Not Satisfiable (Request
If the page cannot provide the request range, the server returns this status code.
417 Expectation Failed (not meeting expectations) the server does not meet the requirements of the "expected" request header field.

5xx (server error)
These status codes indicate an internal error occurred when the server attempted to process the request. These errors may be server errors rather than request errors.

Code Description
500 Internal Server Error (Internal Server Error) The Server encounters an Error and cannot complete the request.
501 Not Implemented (Not Implemented) the server does Not have the function to complete the request. For example, this Code may be returned when the server cannot identify the request method.
502 the Bad Gateway server acts as a Gateway or proxy and receives an invalid response from the upstream server.
503 the Service Unavailable (Service Unavailable) server is currently Unavailable (due to overload or downtime maintenance ). Generally, this is only a temporary status.
The 504 Gateway Timeout server acts as a Gateway or proxy, but does not receive a request from the upstream server in time.
505 the HTTP Version Not Supported server does Not support the HTTP protocol Version used in the request.