HTTP Status Messages
HTTP Status Messages （状态消息）
The users may get an error while sending a request to a server. Definitely, the user has seen such messages frequently. （用户向服务器发送请求时可能出错。毫无疑问，用户经常看到此类消息。）
Here you can find the list of Hypertext Transfer Protocol (HTTP) response status codes. These codes are used to respond to the request of the client made to the server. There are 5 classes of HTTP response status codes. Let’s go through each class:
If you receive a response that is not included in this list, this means that it is a non-standard response, perhaps custom to the software of the server. （>如果您收到的响应未包含在此列表中，这意味着这是一个非标准响应，可能是针对服务器软件的自定义响应。）
1xx: Information
1xx: Information
| Status code | Message | Description |
|---|---|---|
| 100 | Continue | Means that the server has received request headers and the client should continue to send request body. |
| 101 | Switching Protocols | Means that the client, who made a request, has asked the server to change protocols. |
| 103 | Checkpoint | Means that it is used in the resumable requests proposal to resume aborted PUT or POST requests. |
2xx: Successful
2xx: Successful
| Status code | Message | Description |
|---|---|---|
| 200 | OK | Means that the request is OK. It is standard response for successful HTTP requests. |
| 201 | Created | Means that the request has been fulfilled and a new resource is created. |
| 202 | Accepted | Means that the request has been accepted for processing, but the processing is going on. |
| 203 | Non-Authoritative Information | Means that the request has been successfully processed, but it is returning information which may be from another source. |
| 204 | No Content | Means that the request has been successfully processed, but it is not giving any content. |
| 205 | Reset Content | Means that the request has been processed, but it is not returning any content and it requires that the requester reset the document view. |
| 206 | Partial Content | Means that the server commits only a part of the resource, because of a range header, which was sent by the client. |
3xx: Redirection
3xx: Redirection
| Status code | Message | Description |
|---|---|---|
| 300 | Multiple Choices | Is a link list which means that the user can select a link and go there. It can contain maximum five addresses. |
| 301 | Moved Permanently | Means that the page has been moved to a new URL. |
| 302 | Found | Means that the requested page has been moved to a new URL temporarily. |
| 303 | See Other | Means that the requested page can be found in another URL. |
| 304 | Not Modified | Means that the requested page hasn’t been modified since the last request. |
| 306 | Switch Proxy | Is not used anymore. |
| 307 | Temporary Redirect | Means that the requested page has been moved to a new URL temporarily. |
| 308 | Resume Incomplete | Is used in resumable requests proposal to continue aborted PUT or POST requests. |
4xx: Client Error
4xx: Client Error
| Status code | Message | Description |
|---|---|---|
| 400 | Bad Request | Means that the request can be fulfilled because of the bad syntax. |
| 401 | Unauthorized | Means that the request was legal, but the server is rejecting to answer it. For the use when authentication is required and has failed or has not yet been provided. |
| 402 | Payment Required | Is reserved for a future use. |
| 403 | Forbidden | Means that the request is legal, but the server is rejecting to answer it. |
| 404 | Not Found | Means that the requested page cannot be found at the moment, but it may be available again in the future. |
| 405 | Method Not Allowed | Means that the request was made of a page that uses an unsupported request method for that page. |
| 406 | Not Acceptable | Means that the server can only generate an answer which the client doesn’t accept. |
| 407 | Proxy Authentication Required | Means that the client first authenticate itself with the proxy. |
| 408 | Request Timeout | Means that the server timed out waiting for the request. |
| 409 | Conflict | Means that the request cannot be completed, because of a conflict in the request. |
| 410 | Gone | Means that the requested page is not available anymore. |
| 411 | Length Required | Means that the content length is not defined and the server won’t accept the request without it. |
| 412 | Precondition Failed | Means that precondition, which is given in the request, is evaluated to false by the server. |
| 413 | Request Entity Too Large | Means that the request entity is too large and that’s why the server won’t accept the request. |
| 414 | Request-URI Too Long | Means that the URL is too long and that’s why the server won’t accept the request. It happens when you convert a POST request to a GET request with a long query information. |
| 415 | Unsupported Media Type | Means that the media type is not supported and that’s why the server won’t accept the request. |
| 416 | Requested Range Not Satisfiable | Means that the client asked for a part of the file but the server cannot supply that part. |
| 417 | Expectation Failed | Means that the server cannot meet the requirements of the expected request header field. |
5xx: Server Error
5xx: Server Error
| Status code | Message | Description |
|---|---|---|
| 500 | Internal Server Error | Is a generic error and users receive this error message when there is no more suitable specific message. |
| 501 | Not Implemented | Means that the server doesn’t recognize the request method or it lacks the ability to fulfill the request. |
| 502 | Bad Gateway | Means that the server was acting as a gateway or proxy and it received an invalid answer from the upstream server. |
| 503 | Service Unavailable | Means that the server is not available now (It may be overloaded or down). |
| 504 | Gateway Timeout | Means that the server was acting as a gateway or proxy and it didn’t get answer on time from the upstream server. |
| 505 | HTTP Version Not Supported | Means that the HTTP protocol version, used in the request, is not supported by the server. |
| 511 | Network Authentication Required | Means that the client needs to authenticate to gain network access. |