HTTP status code

Fav

Message Response

status code	cause phrase	Implications
100	Continue (continued)	客户端应当继续发送请求.this one临时响应是用来通知客户端它的部分请求已经被server (computer)接收,且仍未被拒绝.客户端应当继续发送请求的剩余部分,或者如果请求已经完成,忽略this one响应.server (computer)必须在请求完成后向客户端发送一个最终响应.
101	Switching Protocol (switching protocols)	server (computer)已经理解了客户端的请求，并将通过Upgrade消息头通知客户端采用不同的协议来完成this one请求。在发送完this one响应最后的空行后，server (computer)将会切换到在Upgrade消息头中定义的那些协议。: 只有在切换新的协议更有好处的时候才应该采取类似措施。例如，切换到新的HTTP版本比old version更有优势，或者切换到一个实时且同步的协议以传送利用此类特性的资源。

Successful response

status code	cause phrase	Implications
200	OK (Success)	The request was successful. The meaning of success varies depending on the method used for the request. GET: The resource has been fetched and passed back to the client as a response. HEAD: thing that has a material existence (as opposed a conceptual, virtual or online existence)头has been passed back to the client as a response header POST: After the server has processed the data from the client, the appropriate resources are sent back to the client as a response. TRACE: server (computer)receivedrequest messageis passed back to the client as a response body.
201	Created (Created)	The request was successful and a new resource has been created in response to the request, which is usually the response code from the PUT method.
202	Accepted (Created)	server (computer)已接受请求，但尚未处理。正如它可能被拒绝一样，最终该请求可能会也可能不会被执行。在异步操作的场合下，没有比发送this onestatus code更方便的做法了。:返回202status code的响应的目的是允许server (computer)接受其他过程的请求（例如某个每天只执行一次的基于批处理的操作），而不必让客户端一直保持与server (computer)的连接直到批处理操作全部完成。在接受请求处理并返回202status code的响应应当在返回的thing that has a material existence (as opposed a conceptual, virtual or online existence)中包含一些指示处理当前状态的信息，以及指向处理状态监视器或状态预测的指针，以便用户能够估计操作是否已经完成。
203	Non-Authoritative Information (unauthorized information)	server (computer)已成功处理了请求,但返回的thing that has a material existence (as opposed a conceptual, virtual or online existence)头部元信息不是在原始server (computer)上有效的确定集合，而是来自本地或者第三方的拷贝,如果不是上述情况,使用200status code才是最合适的.
204	No Content (no content)	该响应没有响应内容,只有响应头,响应头也可能是有用的.用户代理可以根据新的响应头来更新对应资源的缓存信息.
205	Reset Content (reset content)	Tells the user agent to reset the document view of the window that sent the request.
206	Partial Content (partial)	This status code is used when the client performs a segmented download of a file by using the range header field

redirects

status code	cause phrase	Implications
300	Multiple Choice (Multiple options)	该请求有多种可能的响应,用户代理或者用户必须选择它们其中的一个.server (computer)没有任何标准可以遵循去代替用户来进行选择.
301	Moved Permanently (permanent movement)	This status code indicates that the path to the requested URI resource has changed, and the new URL will be added to the response's`Location`:: Found in the header field.
302	Found (temporary movement)	this state码表示所请求的URI资源路径临时改变,并且还可能继续改变.因此客户端在以后访问时还得继续使用该URI.新的URL会在响应的`Location:`Find in the header field.
303	See Other (View other locations)	The server sends this response to direct the client to another URI using the GET method.
304	Not Modified (Unmodified)	Tells the client that the requested content has not changed since the last visit. The client can fetch the resource directly from the browser cache.
305	Use Proxy (using proxies)	The requested resource must be accessed through a proxy. This status code is not widely supported for security reasons.
306	unused (unused)	this onestatus codeNo longer in use,When it was first used在HTTP 1.1 specification的old version中.
307	Temporary Redirect (Temporary redirection)	server (computer)发送该响应用来引导客户端使用相同的方法访问另外一个URI来获取想要获取的资源.新的URL会在响应的`Location:`Find in the header field.与302status code有相同的语义,且前后两次访问必须使用相同的方法(GET POST).
308	Permanent Redirect (permanent redirect)	The requested resource will be permanently located at another URI. The new URL will be added to the`Location:`Find in the header field.与301status code有相同的语义,且前后两次访问必须使用相同的方法(GET POST).

client-side error

status code	cause phrase	Implications
400	Bad Request (Error request)	The server could not read the request because it was sent with a syntax error.
401	Unauthorized (unauthorized)	需要身份验证后才能获取所请求的内容,类似于403错误.不同点是.401错误后,只要正确输入帐号密码,验证即可通过.
402	Payment Required (Payment required)	this state码constitute a reservationFor future use.Create this codeThe original purpose was to为numericFor payment systems,However, it's still not in use..
403	Forbidden (Access denied)	The client does not have the right to access the requested content and the server rejects the request.
404	Not Found (not found)	The server could not find the requested resource. Because this happens so often, this status code is very common when surfing the web.
405	Method Not Allowed (The use of this method is not allowed.)	This request uses a method that is prohibited on the server side, as specified in RFC 2616. `GET` respond in singing `HEAD` method cannot be disabled.
406	Not Acceptable (Unacceptable)	underwayServer-driven content negotiationAfter that, no suitable content was found to be passed back to the client.
407	Proxy Authentication Required (Requires proxy authentication)	Similar to status code 401, but requires a proxy to authenticate.
408	Request Timeout (Request timeout)	客户端没有在server (computer)预备等待的时间内完成一个请求的发送.这意味着server (computer)将会切断respond in singing客户端的连接. 在其他浏览器中,这种响应更常见一些, 例如Chrome respond in singing IE9, 目的是为了使用HTTP 预连机制Speed up browsing. Also note that some servers simply disconnect without sending such a response.
409	Conflict (Conflict)	The request conflicts with the current state of the server.
410	Gone (lapsed)	The requested resource has been deleted.
411	Length Required (Content length header required)	Because the server needs to be in this request `Content-Length` header field, which was not sent by the client. Therefore, the server rejects the request.
412	Precondition Failed (Pre-processing failure)	The server did not fulfill the preconditions set by the client in the request header field when obtaining the resource.
413	Request Entity Too Large (Requesting entity is too long)	If the size of the requesting entity exceeds the maximum limit set by the server, the server may close the HTTP link and return the`Retry-After` Header fields.
414	Request-URI Too Long (Request URL too long)	The client request contains a URI address that is too long for the server to process.
415	Unsupported Media Type (Media type not supported)	The server does not support the media type requested by the client and therefore rejects the request.
416	Requested Range Not Satisfiable (The scope of the request is not required)	The request contains the`Range`The header field cannot be satisfied, usually because the`Range`The range of numbers in the request exceeds the size of the requested resource.
417	Expectation Failed (Failure of expected results)	In the request header `Expect` The expected content specified in the
418	I'm a teapot (The server refuses to make coffee in a teapot.)	超文本咖啡壶控制协议（英语：Hyper Text Coffee Pot Control Protocol，缩写HTCPCP）是由IETF虚构的一种协议。this one协议在文档RFC 2324（1998年4月1日发布）中定义，是一个恶搞RFC。该协议被设计为一个类似HTTP的协议，可以用于控制、监测respond in singing诊断咖啡壶，后来也被拓展到茶壶；该协议有时也可以视作一种早期的物联网实验。

server-side error

status code	cause phrase	Implications
500	Internal Server Error (Internal server error)	The server is experiencing unknown and unsolvable problems.
501	Not Implemented (not realized)	The server does not support the methods used in this request, such as`POST` respond in singing `PUT. onlyGET` respond in singing `HEAD` is a method that must be implemented by the server as specified in the RFC2616 specification.
502	Bad Gateway (Gateway error)	The server acts as a gateway and receives data from the upstreamThe server got an invalid HTTP response.
503	Service Unavailable (Service unavailable)	由于临时的server (computer)维护或者过载,server (computer)当前无法处理请求.this one状况是临时的,并且将在一段时间以后恢复.如果能够预计延迟时间,那么响应中可以包含一个`Retry-After:`header to indicate this delay. If this is not given, the`Retry-After:`信息，那么客户端应当以处理500响应的方式处理它.同时,这种情况下,一个友好的用于解释server (computer)出现问题的页面应当被返回,并且,缓存相关的HTTP头信息也应该包含,因为通常这种错误提示网页不应当被客户端缓存.
504	Gateway Timeout (Gateway timeout)	The server acts as a gateway and cannot be accessed from the upstreamserver (computer)The response is returned to the client in a timely manner.
505	HTTP Version Not Supported (HTTP version not supported)	The server does not support the version of the HTTP protocol used in the HTTP request sent by the client.

Introduction to HTML Status Codes:

1. In the HTTP protocol, a status code is a set of numbers used to indicate the status of the server’s response to a client’s request.

2. Status codes are typically divided into the following five categories:

① Informational status codes (100–199): Indicate that the server has received the request and is processing it, but has not yet completed the process.

② Success status codes (200–299): Indicate that the request was successful and the server has returned the requested data.

③ Redirect status codes (300–399): Indicates that the request has been redirected to another URL.

④ Client Error Status Codes (400–499): Indicates that the request contains syntax errors or cannot be understood by the server.

⑤ Server Error Status Codes (500–599): Indicates that the server encountered a problem and cannot complete the request.