The status code of the http protocol
1xx (provisional response)
A status code that represents a provisional response and requires the requester to continue with the operation.
| 100 (continued) |
The requester should proceed with the request. The server returns this code to indicate that the first part of the request has been received and is waiting for the rest. |
| 101 (Switching Protocol) |
The requester has asked the server to switch protocols, the server has confirmed and is ready to switch. |
2xx (success)
is a status code indicating that the request was successfully processed.
| 200 (success) |
The server has successfully processed the request. Typically, this means that the server served the requested web page. If this status code is displayed for your robots.txt file, it means that Googlebot has successfully retrieved the file. |
| 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 (unauthorized information) |
The server has successfully processed the request, but the returned information may have come from another source. |
| 204 (no content) |
The server successfully processed the request, but returned nothing. |
| 205 (reset content) |
The server successfully processed the request, but returned nothing. Unlike the 204 response, this response requires the requester to reset the document view (eg, clear the form content to enter new content). |
| 206 (partial content) |
The server successfully processed part of the GET request. |
3xx (redirect)
To complete the request, further action is required. Typically, these status codes are used for redirection. Google recommends that you use no more than 5 redirects per request. You can use Webmaster Tools to see if Googlebot is having trouble crawling redirected pages. The Web Crawl page under Diagnostics lists URLs that Googlebot could not crawl due to redirect errors.
| 300 (many options) |
In response to the request, the server can perform various operations. The server may select an action based on the requestor (user agent), or provide a list of actions for the requester to choose from. |
| 301 (Moved Permanently) |
The requested webpage has been permanently moved to a new location. When the server returns this response (to a GET or HEAD request), it automatically redirects the requester to the new location. You should use this code to tell Googlebot that a page or site has been permanently moved to a new location. |
| 302 (temporary move) |
The server is currently responding to requests from the web page in a different location, but the requester should continue to use the original location for future requests. This code is similar to the 301 code in response to GET and HEAD requests and will automatically send the requester to a different location, but you should not use this code to tell Googlebot that a page or site has moved, as Googlebot will continue to crawl the original location and indexing. |
| 303 (see other locations) |
The server returns this code when the requester should use separate GET requests for different locations to retrieve the response. For all requests except HEAD, the server automatically goes elsewhere. |
| 304 (unmodified) |
The requested page has not been modified since the last request. When the server returns this response, no web page content is returned. |
| 305 (using 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 a proxy. |
| 307 (temporary redirect) |
The server is currently responding to requests from the web page in a different location, but the requester should continue to use the original location for future requests. This code is similar to the <a href=answer.py?answer=>301</a> code that responds to GET and HEAD requests and will automatically take the requester to a different location, but you should not use this code to tell Googlebot something pages or sites have moved because Googlebot will continue to crawl and index where they were. |
4xx（请求错误）
这些状态码表示请求可能出错，妨碍了服务器的处理。
| 400（错误请求） |
服务器不理解请求的语法。 |
| 401（未授权） |
请求要求身份验证。对于登录后请求的网页，服务器可能返回此响应。 |
| 403（禁止） |
服务器拒绝请求。如果您在 Googlebot 尝试抓取您网站上的有效网页时看到此状态码（您可以在 Google 网站管理员工具诊断下的网络抓取页面上看到此信息），可能是您的服务器或主机拒绝了 Googlebot 访问。 |
| 404（未找到） |
服务器找不到请求的网页。例如，对于服务器上不存在的网页经常会返回此代码。 |
| 405（方法禁用） |
禁用请求中指定的方法。 |
| 406（不接受） |
无法使用请求的内容特性响应请求的网页。 |
| 407（需要代理授权） |
此状态码与 <a href=answer.py?answer=35128>401（未授权）</a>类似，但指定请求者应当授权使用代理。如果服务器返回此响应，还表示请求者应当使用代理。 |
| 408（请求超时） |
服务器等候请求时发生超时。 |
| 409（冲突） |
服务器在完成请求时发生冲突。服务器必须在响应中包含有关冲突的信息。服务器在响应与前一个请求相冲突的 PUT 请求时可能会返回此代码，以及两个请求的差异列表。 |
| 410（已删除） |
如果请求的资源已永久删除，服务器就会返回此响应。该代码与 404（未找到）代码类似，但在资源以前存在而现在不存在的情况下，有时会用来替代 404 代码。如果资源已永久移动，您应使用 301 指定资源的新位置。 |
| 411（需要有效长度） |
服务器不接受不含有效内容长度标头字段的请求。 |
| 412（未满足前提条件） |
服务器未满足请求者在请求中设置的其中一个前提条件。 |
| 413（请求实体过大） |
服务器无法处理请求，因为请求实体过大，超出服务器的处理能力。 |
| 414（请求的 URI 过长） |
请求的 URI（通常为网址）过长，服务器无法处理。 |
| 415（不支持的媒体类型） |
请求的格式不受请求页面的支持。 |
| 416（请求范围不符合要求） |
如果页面无法提供请求的范围，则服务器会返回此状态码。 |
| 417（未满足期望值） |
服务器未满足”期望”请求标头字段的要求。 |
5xx（服务器错误）
这些状态码表示服务器在处理请求时发生内部错误。这些错误可能是服务器本身的错误，而不是请求出错。
| 500（服务器内部错误） |
服务器遇到错误，无法完成请求。 |
| 501（尚未实施） |
服务器不具备完成请求的功能。例如，服务器无法识别请求方法时可能会返回此代码。 |
| 502（错误网关） |
The server, acting as a gateway or proxy, received an invalid response from an upstream server. |
| 503 (Service unavailable) |
The server is currently unavailable (due to overloading or downtime for maintenance). Usually, this is only a temporary state. |
| 504 (Gateway Timeout) |
The server acts as a gateway or proxy, but does not receive a request from the upstream server in a timely manner. |
| 505 (HTTP version not supported) |
The server does not support the HTTP protocol version used in the request. |