| 1** | Informational | |
|---|
| 100 | Continue | Server has received request headers and client should proceed to send the request body |
| 101 | Switching Protocols | Requester has asked server to switch protocols and the server has agreed to do so |
| 102 | Processing (WebDAV; RFC 2518) | A WebDAV request may contain many subrequests; this response keeps the client from disconnecting due to timeout |
| 103 | Checkpoint [Unofficial] | Used in the resumable requests proposal to resume aborted PUT or POSTS requests |
| 103 | Early Hints [Unofficial] | Used to return some response headers before entire HTTP response |
| 2×× | Success | |
|---|
| 200 | OK | Standard response for successful HTTP requests |
| 201 | Created | Request has been fulfilled resulting in the creation of a new resource |
| 202 | Accepted | Request has been accepted for processing but the processing has not been completed (request may or may not be completed and may be disallowed when processing occurs) |
| 203 | Non-authoritative Information | The server is a transforming proxy that received a 200 OK from its origin, but is returning a modified version of the origin’s response |
| 204 | No Content | The server successfully processed the request and is not returning any content |
| 205 | Reset Content | Same as 204 but the requester is required to reset the document view |
| 206 | Partial Content (RFC 7233) | The server is delivering only part of the resource (e.g. byte serving) due to a range header sent by the client (used to resume downloads or split a download into multiple streams) |
| 207 | Multi-Status (WebDAV; RFC 4918) | Message body contains an XML message that can contain separate response codes depending on how many sub-requests were made |
| 208 | Already Reported (WebDAV; RFC 5842) | The members of a DAV binding have already been enumerated in a preceding part of the (multistatus) response, and are not being included again |
| 226 | IM Used (RFC 3229) | The server has fulfilled the request for a resource, and the response is a representation of the result of one or more Instance Manipulations applied to the current instance |
| 3×× | Redirection | |
|---|
| 300 | Multiple Choices | Multiple options for the resource exist from which the client may choose (agent-driven content negotiation) |
| 301 | Moved Permanently | This and all future requests should be directed to the given URI |
| 302 | Found | WARNING: Industry practice contradicts standard. RFC 1945 defined it as “Moved Temporarily”, industry implemnted it as 303. Treat a 302 like a 303 but send a 307 if you mean a Temporary Redirect |
| 303 | See Other | Response to the request can be found under another URI using a GET method. In response to PUT or POST, indicates the server has performed the operation and the results can be obtained via GET |
| 304 | Not Modified (RFC 7232) | Resource has not been modified since the version specified by the request headers If-Modified-Since or If-None-Match, no content is sent and client should use previously downloaded copy |
| 305 | Use Proxy | WARNING: Many browsers deliberately do not handle this correctly due to security concerns. Resource is available only through a proxy, the address for which is is provided in the response |
| 307 | Temporary Redirect | Request should be repeated with the provided URI; however future requests should still use the original URI. Differs from 302 in that request VERB does not change, e.g. repeat the PUT or POST |
| 308 | Permanent Redirect (RFC 7538) | Request and all future requests should be repeated using another URI. Unlike 301, request method must not change, e.g. resubmit a POSTed form at the new URI via POST if you get a 308 |
| 4×× | Client Error | |
|---|
| 400 | Bad Request | Server cannot or will not process the request due to an apparent client error |
| 401 | Unauthorized | Authentication IS required and has failed or has not yet been provided |
| 402 | Payment Required | Reserved for future use which has never come into existence. Google Dev API uses this if a developer exceeds the daily limit on requests |
| 403 | Forbidden | Request was valid but server is refusing action. User might not have the necessary permissions for a resource |
| 404 | Not Found | Requested resource was not found but may be available in the future. Subsequent requests by the client are permissible |
| 405 | Method Not Allowed | Request method is not supported for the requested resource such as a GET on a POST form or a PUT on a read-only resource |
| 406 | Not Acceptable | Requested resource is capable of generating only content not acceptable according to the Accept headers sent in the request |
| 407 | Proxy Authentication Required (RFC 7235) | Client must first authenticate itself with the proxy |
| 408 | Request Timeout | Server timed out waiting for the request. Client may repeat the request without modifications at a later time |
| 409 | Conflict | Request could not be processed because of conflict int he request, such as an edit conflict between multiple simultaneous updates |
| 410 | Gone | Requested resource is unavailable and will not be available again. Should only be used when a resource has been intentionally removed |
| 411 | Length Required | Request did not specify the length of its content, which is required by the requested resource |
| 412 | Precondition Failed (RFC 7232) | Server does not meet one of the preconditions that the requester put on the request |
| 413 | Payload Too Large (RFC 7231) | The request is larger than the server is willing or able to process. Previously called “Request Entity Too Large” |
| 414 | Request-URI Too Long (RFC 7231) | The URI was too long for the server to process. Previously called “Request-URI Too Long” |
| 415 | Unsupported Media Type | Request entity has a media type which the server or resource does not support, e.g. uploading an image in an unacceptable format |
| 416 | Range Not Satisfiable (RFC 7233) | The client has asked for a portion of the file (byte serving) but the server cannot supply that portion (e.g. range goes past EOF) |
| 417 | Expectation Failed | The server cannot meet the requirements of the Expect request-header field |
| 418 | I’m a teapot (RFC 2324) | 1998 IETF April Fool’s joke. Should be returned by teapots requested to brew coffee. Many servers support it as an easter egg |
| 420 | Enhance Your Calm (Twitter) [Unofficial] | Used by version 1 of the Twitter Search and Trends API to implement rate limiting. Versions 1.1 and later use 429 Too Many Requests |
| 420 | Method Failure (Spring Framework) [Unofficial] | A deprecated response used by the Spring Framework when a method has failed |
| 421 | Misdirected Request (RFC 7540) | Request was directed at a server that is not able to produce a response, e.g. because of reused connection |
| 422 | Unprocessable Entity (WebDAV; RFC 4918) | The request was well-formed but was unable to be followed due to semantic errors |
| 423 | Locked (WebDAV; RFC 4918) | The resource that is being accessed is locked |
| 424 | Failed Dependency (WebDAV; RFC 4918) | Request failed due to a failure of a previous request, e.g. a PROPPATCH |
| 426 | Upgrade Required | Client should switch to a different protocol such as TL/1.0, given in the Upgrade header field |
| 428 | Precondition Required (RFC 6585) | Origin server requires the request to be conditional. Intended to prevent the “lost update” problem when treating GET/change/PUT as atomic |
| 429 | Too Many Requests (RFC 6585) | The user has sent too many requests in a given amount of time. Intended for use with rate-limiting schemes |
| 431 | Request Header Fields Too Large (RFC 6585) | Server is unwilling to process the request because either an individual header field, or all fields collectively, are too large |
| 444 | Connection Closed Without Response | |
| 450 | Blocked by Windows Parental Controls (Microsoft) [Unofficial] | |
| 451 | Unavailable For Legal Reasons (RFC 7725) | Server operator has received a legal demand to deny access to a resource. Chosen as a reference to Farenheit 451 |
| 498 | Invalid Token (Esri) [Unofficial] | Returned by ArcGIS for Server, indicates expired or otherwise invalid token |
| 499 | Token Required (Esri) [Unofficial] | Returned by ArcGIS for Server, indicates token is required but was not submitted |
| 5×× | Server Error | |
|---|
| 500 | Internal Server Error | A generic error message, given when an unexpected condition was encountered and no more specific message is suitable |
| 501 | Not Implemented | Server does not recognize the request method or lacks the ability to fulfil it, but wishes to imply future availability |
| 502 | Bad Gateway | Server was acting as a gateway or proxy and received an invalid response from the upstream server |
| 503 | Service Unavailable | The server is currently unavailable because it is overloaded or down for maintenance. Implies temporary state |
| 504 | Gateway Timeout | The server was acting as a gateway or proxy and did not receive a timely response from the upstream server |
| 505 | HTTP Version Not Supported | The server does not support the HTTP protocol version used in the request |
| 506 | Variant Also Negotiates (RFC 2295) | Transparent content negotiation for the request results in a circular reference |
| 507 | Insufficient Storage (WebDAV; RFC 4918) | The server us unable to store the representation needed to complete the request |
| 508 | Loop Detected (WebDAV; RFC 5842) | The server detected an infinite loop while processing the request (sent in lieu of 208 Already Reported) |
| 509 | Bandwidth Limit Exceeded (Apache Web Server/cPanel) [Unofficial] | Server has exceeded the bandwidth specified by the server administrator (i.e. shared hosting provider) |
| 510 | Not Extended (RFC 2774) | Further extensions to teh request are required for the server to fulfill it |
| 511 | Network Authentication Required (RFC 6585) | The client needs to authenticate to gain netowrk access. Used by “captive portals” to require ToS before enabling access via a WiFi Hotspot |
| 530 | Site is frozen (Pantheon web platform) [Unofficial] | Used by Pantheon web platform to indicate a site that has been frozen due to inactivity |
| 598 | Network Read Timeout Error (Informal convention) [Unofficial] | Used by some HTTP proxies to signal a network read timeout behind the proxy to a client in front of the proxy |
| 599 | Network Connect Timeout Error (Informal convention) [Unofficial] | Used to indicate when the connection to the network times out |