| 100 | Continue — the client should send the following part of a multi-part request. |
| 101 | Switching Protocols — the server is changing the version or type of protocol used in this communication. |
| 200 | OK — the server has received and completed the client's request. |
| 201 | Created — the server has accepted the request and created a new resource, which is available under the URI in the Location header. |
| 202 | Accepted — the server has received and accepted the client's request, but it has not yet started or completed processing. |
| 203 | Non-Authoritative Information — the server is returning data that may be a sub- or superset of the information available on the original server. Mainly used by proxies. |
| 204 | No Content — used in place of 200 (OK) when there is no body to the response. |
| 205 | Reset Content — identical to 204 (No Content), but the client should reload the active document view. |
| 206 | Partial Content — used in place of 200 (OK) when the client requested a Range header. |
| 300 | Multiple Choices — the requested resource is available at multiple URIs, and the client should redirect the request to a URI specified in the list in the message body. |
| 301 | Moved Permanently — the requested resource is no longer available at this URI, and the client should redirect this and all future requests to the URI specified in the Location header. |
| 302 | Found — the resource temporarily resides under a different URI. This request should be redirected on user confirmation to the URI in the Location header, but future requests should not be altered. |
| 303 | See Other — very similar to 302 (Found), but does not require user input to redirect to the provided URI. The provided URI should be retrieved with a GET request. |
| 304 | Not Modified — the client sent an If-Modified-Since or similar header, and the resource has not been modified since that point; the client should display a cached copy of the resource. |
| 305 | Use Proxy — the requested resource must be requested again through the proxy specified in the Location header field. |
| 307 | Temporary Redirect — identical to 302 (Found), but HTTP 1.0 clients do not support 307 responses. |
| 400 | Bad Request — the client sent a malformed request containing syntax errors, and should modify the request to correct this before repeating it. |
| 401 | Unauthorized — the requested resource is not available without authentication. The client may repeat the request using an Authorization header to provide authentication details. |
| 402 | Payment Required — reserved, unspecified status code for use by applications that require user subscriptions to view content. |
| 403 | Forbidden — the server understands the request, but refuses to fulfil it due to existing access controls. The request should not be repeated. |
| 404 | Not Found — there is no resource available on this server that matches the requested URI. May be used in place of 403 to avoid exposing access control details. |
| 405 | Method Not Allowed — the resource does not support the request method (HTTP verb); the Allow header lists acceptable request methods. |
| 406 | Not Acceptable — the resource has characteristics that violate the accept headers sent in the request. |
| 407 | Proxy Authentication Required — similar to 401 (Unauthorized), but indicates that the client must first authenticate with the intermediate proxy. |
| 408 | Request Timeout — the server expected another request from the client, but none were provided within an acceptable timeframe. |
| 409 | Conflict — the request could not be completed because it conflicted with the current state of the resource. |
| 410 | Gone — similar to 404 (Not Found), but indicates a permanent removal. No forwarding address is available. |
| 411 | Length Required — the client did not specify a valid Content-Length header, and must do so before the server will accept this request. |
| 412 | Precondition Failed — the resource is not available with all the conditions specified by the conditional headers sent by the client. |
| 413 | Request Entity Too Large — the server is presently unable to process a message body of the length that the client sent. |
| 414 | Request-URI Too Long — the server is refusing the request because the Request-URI is longer than the server is willing to interpret. |
| 415 | Unsupported Media Type — the server does not support the MIME or media type specified by the client, and cannot service this request. |
| 416 | Requested Range Not Satisfiable — the client requested a range of bytes, but the server cannot provide content to that specification. |
| 417 | Expectation Failed — the client specified constraints in the Expect header that the server cannot meet. |
| 500 | Internal Server Error — the server met an unexpected condition or error which prevents it from completing this request. |
| 501 | Not Implemented — the server does not support the functionality required to complete the request. Usually used to indicate a request method that is not supported on any resource. |
| 502 | Bad Gateway — the server is a proxy, and received an invalid response from the upstream server while processing this request. |
| 503 | Service Unavailable — the server is under high load or undergoing maintenance, and does not have the capacity to serve this request at present. |
| 504 | Gateway Timeout — the server is a proxy, and did not receive a response from the upstream server in a timely manner. |
| 505 | HTTP Version Not Supported — the server does not support the version of the HTTP protocol that the client made its request with. |
