HTTP status Code explanation

What is an HTTP status code

The HTTP status code is used by the Web server to tell the client what has happened.

The status code, located in the first line of HTTP Response, returns a "three-digit status code" and a "status message." The "three-digit status code" is easy for the program to process, and "status messages" are easier to understand.

Defined range	Classification
1XX	100-101	Information Tips
2XX	200-206	Success
3XX	300-305	redirect
4XX	400-415	Client Error
5XX	500-505	Server error

4XX Client Error status code

Status code	Status messages	Meaning
400	Bad Request	Tells the client that it sent an incorrect request.
401	Unauthorized (not authorized)	Requires the client to authenticate itself
402	Payment Required (Requires payment)	This state has not been used and is reserved for future use
403	Forbidden (Forbidden)	The request was rejected by the server
50U	Not Found (not found)	Resource not Found
405	Method not allowed (methods not allowed)	The method of the request is not supported.
50W	Not acceptable (unacceptable)
407	Proxy authentication Required (requires agent authentication)	Similar to status code 401 for proxy servers that require authentication
408	Request Timeout (requests timed out)	If the client takes too long to complete the request, the server can echo the status code and close the connection
409	Conflict (conflict)	The request caused some conflict on the resource
410	Gone (disappeared)	The server used to have this resource, and now it's gone, similar to status code 404
411	Length Required (requires long indication)	The server requires that Content-length be included in the request.
412	Precondition Failed (Prerequisite failure)
413	Request entity Too Large (requesting entities too large)	The entity body part sent by the client is larger than the server can or wants to handle
414	Request URI Too Long (requests URI is too lengthy)	The client sends a request with a URL that exceeds the length that the server can or wants to process
415	Unsupported media type (not supported)	The server does not understand or does not support the content type of the entity sent by the client
416	Requested range not satisfiable (the requested range is not met)
417	Expectation Failed (unable to meet expectations)

5XX Server Error Status code

Status code	Status messages	Meaning
500	Internal Server error (internal server errors)	The server encountered an error that prevented it from serving the request
501	Not implemented (not implemented)	This status code is used when a client-initiated request exceeds the capabilities of the server (for example, using a request method that is not supported by the server).
502	Bad Gateway (gateways fail)	The server used by the agent encountered an invalid upstream response
503	Service Unavailable (not available)	The server is currently unable to service the request, but can recover the service over time
504	Gateway Timeout (gateways timed out)	Similar to the status 408, but the response comes from the gateway or proxy, and this gateway or proxy has timed out while waiting for the response from another server
505	HTTP version not supported (HTTP versions not supported)	The server received a request that uses an HTTP protocol version that it does not support. Some servers do not support HTTP earlier HTTP protocol versions, nor do they support too high protocol versions

Common Status Codes

Status code	Status messages	Meaning
200	Ok	The server successfully processed the request (this is the most we have seen)
201	Created (created)	The resource has been created for requests that require the server to create objects.
202	Accepted (accepted)	The request has been accepted, but the server has not yet processed
203	Non-authoritative Information (non-authoritative information)	The server has successfully processed the transaction, except that the entity header contains information that is not from the original server but from a copy of the resource.
204	No content (no contents)	Response contains headers and a status line, but does not include the subject content of the entity (no response body)
205	Reset content (Reset contents)	Another code that is primarily used for browsers. This means that the browser should reset all the HTML forms on the current page.
206	Partial content (partial)	Partial request succeeded

3XX REDIRECT Status code

The URL of the

Status code	Status messages	Meaning	Instance
+	multiple Choices (multiple selection)	client requests a URL that actually points to multiple resources. This code is returned with a list of options, and then the user can select the option he wants
301	Moved permanently (permanently removed)	request was moved. The response should contain a location URL that explains where the resource is now located
302	Found (found)	Code 301 is similar. But the removal here is temporary. The client will resend the new HTTP request	using the URL given in location,
303	see Other (see other)	similar to 302
304	not Modified (unmodified)	client's cache resource is up-to-date for clients to use the cache
305	use proxy (using proxy)	must access the resource through the proxy, the address of the agent in the Loc of response ation
306	not used	This status code is not currently used
307	Temporary Redirect (temporary redirect	similar to 302

2XX Success Status Code

Status code	Status messages	Meaning	Instance
200	Ok	The server successfully processed the request (this is the most we have seen)
201	Created (created)	The resource has been created for requests that require the server to create objects.
202	Accepted (accepted)	The request has been accepted, but the server has not yet processed
203	Non-authoritative Information (non-authoritative information)	The server has successfully processed the transaction, except that the entity header contains information that is not from the original server but from a copy of the resource.
204	No content (no contents)	Response contains headers and a status line, but does not include the subject content of the entity (no response body)
205	Reset content (Reset contents)	Another code that is primarily used for browsers. This means that the browser should reset all the HTML forms on the current page.
206	Partial content (partial)	Partial request succeeded

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HTTP status Code explanation