HTTP response status codes indicate whether a specific HTTP request has been completed. Responses are all grouped together into 5 groups: informational responses, redirects, successful responses, client errors, and servers errors.

Information responses

100 Continue

This response indicates that everything so far is okay and is working fine and that the client should continue with the request or ignore this response it if it is already complete.

101 Switching Protocol

This code is sent to respond from an upgrade request header by the client and indicates the protocol the server is switching to.

102 Processing

The clue is in the name. This code indicates that the server has received and is processing the request send by the client, but no response is available yet.

103 Early Hints

This status code is primarily intended to be used with the Link header to allow the user agent to start preloading resources while the server is still preparing a response.

Successful responses

200 OK

The request has succeeded. The meaning of a success varies depending on the HTTP method

201 Created

The request has succeeded and a new resource has been created as a result of it. This is typically the response sent after a POST request, or after some PUT requests.

202 Accepted

The request has been received but not yet acted upon. It is non-committal, meaning that there is no way in HTTP to later send an asynchronous response indicating the outcome of processing the request.

203 Non-Authoritative Information

This response code means returned meta-information is not an exact set as available from the origin server but collected from a local or a third-party copy.

204 No Content

There is no content to send for this request, but the headers may be useful. 

205 Reset Content

This response code is sent after accomplishing request to tell the user agent to reset the document view which sent this request.

 

206 Partial Content

This response code is used because of the range header sent by the client to separate download into multiple streams.

207 Multi-Status

A Multi-Status response conveys information about multiple resources in situations where multiple status codes might be appropriate.

208 Multi-Status

avoid enumerating the internal members of multiple bindings to the same collection repeatedly.

226 IM Used

the server has fulfilled a ‘GET’ request for the resource, and the response is a representation of the result of one or more instance-manipulations applied to the current instance.

Redirection messages

300 Multiple Choice

The request has more than one possible response. The user-agent or user should choose one of them. There is no standardized way of choosing one of the responses.

301 Moved Permanently

This response code means that the URI of the requested resource has been changed permanently.

302 Found

This response code means that the URI of the requested resource has been changed temporarily.

303 See Other

The server sent this response to direct the client to get the requested resource at another URI with a GET request.

304 Not Modified

This is used for caching purposes. It tells the client that the response has not been modified, so the client can continue to use the same cached version of the response.

305 Use Proxy

Was defined in a previous version of the HTTP specification to indicate that a requested response must be accessed by a proxy.

306 unused

This response code is no longer used, it is just reserved currently.

307 Temporary Redirect

The server sends this response to direct the client to get the requested resource at another URI with the same method that was used in the prior request.

308 Permanent Redirect

This means that the resource is now permanently located at another URI, specified by the Location: HTTP Response header. 

Client error responses

400 Bad Request

This response means that the server could not understand the request due to invalid syntax.

401 Unauthorized

Although the HTTP standard specifies “unauthorized”, semantically this response means “unauthenticated”. That is, the client must authenticate itself to get the requested response.

402 Payment Required

This response code is reserved for future use. Initial aim for creating this code was using it for digital payment systems, however, this status code is used very rarely and no standard convention exists.

403 Forbidden

The client does not have access rights to the content, i.e. they are unauthorized, so the server is rejecting to give a proper response. Unlike 401, the client’s identity is known to the server.

404 Not Found

The server can not find the requested resource. In the browser, this means the URL is not recognized.

405 Method Not Allowed

The request method is known by the server but has been disabled and cannot be used.

406 Not Acceptable

This response is sent when the web server, after performing server-driven content negotiation, doesn’t find any content following the criteria given by the user agent.

407 Proxy Authentication Required

This is similar to 401 but authentication is needed to be done by a proxy.

408 Request Timeout

This response is sent on an idle connection by some servers, even without any previous request by the client.

409 Conflict

This response is sent when a request conflicts with the current state of the server.

410 Gone

This response would be sent when the requested content has been permanently deleted from the server, with no forwarding address.

411 Length Required

The server rejected the request because the Content-Length header field is not defined and the server requires it.

412 Precondition Failed

The client has indicated preconditions in its headers which the server does not meet.

413 Payload Too Large

Request entity is larger than limits defined by the server; the server might close the connection or return a Retry-After header field.

414 URI Too Long

The URI requested by the client is longer than the server is willing to interpret.

415 Unsupported Media Type

The media format of the requested data is not supported by the server, so the server is rejecting the request.

416 Requested Range Not Satisfiable

The range specified by the Range header field in the request can’t be fulfilled; it’s possible that the range is outside the size of the target URI’s data.

417 Expectation Failed

This response code means the expectation indicated by the Expect request-header field can’t be met by the server.

418 I’m a teapot

The server refuses the attempt to brew coffee with a teapot.

 

421 Misdirected Request

The request was directed at a server that is not able to produce a response

422 Unprocessable Entity

The request was well-formed but was unable to be followed due to semantic errors.

423 Locked

The resource that is being accessed is locked.

424 Failed Dependency

The request failed due to failure of a previous request.

425 Too Early

Indicates that the server is unwilling to risk processing a request that might be replayed.

426 Upgrade Required

The server refuses to perform the request using the current protocol but might be willing to do so after the client upgrades to a different protocol.

428 Precondition Required

The origin server requires the request to be conditional. 

429 Too Many Requests

The user has sent too many requests in a given amount of time (“rate limiting”).

431 Request Header Fields Too Large

The server is unwilling to process the request because its header fields are too large. The request MAY be resubmitted after reducing the size of the request header fields.

451 Unavailable For Legal Reasons

The user requests an illegal resource, such as a web page censored by a government.

Server error responses

500 Internal Server Error

The server has encountered a situation it doesn’t know how to handle.

 501 Not Implemented

The request method is not supported by the server and cannot be handled

502 Bad Gateway

This error response means that the server while working as a gateway to get a response needed to handle the request, got an invalid response.

503 Service Unavailable

The server is not ready to handle the request. Common causes are a server that is down for maintenance or that is overloaded.

504 Gateway Timeout

This error response is given when the server is acting as a gateway and cannot get a response in time.

505 HTTP Version Not Supported

The HTTP version used in the request is not supported by the server.

506 Variant Also Negotiates

The server has an internal configuration error: transparent content negotiation for the request results in a circular reference.

507 Insufficient Storage

The server has an internal configuration error

508 Loop Detected

The server detected an infinite loop while processing the request.

510 Not Extended

Further extensions to the request are required for the server to fulfil it.

511 Network Authentication Required

The 511 status code indicates that the client needs to authenticate to gain network access.