Developer Reference

HTTP Status Codes

Every HTTP status code a backend developer needs — what it means, why it happens, and how to fix it. Click any code for details and examples.

Most common

200OKThe request succeeded. The meaning of success depends on the HTTP me…201CreatedThe request succeeded and a new resource was created as a result. Co…204No ContentThe request succeeded but there is no content to return in the respo…301Moved PermanentlyThe resource has been permanently moved to a new URL. Search engines…302FoundThe resource is temporarily at a different URL. The original URL sho…304Not ModifiedThe cached version of the resource is still valid, so the server ret…400Bad RequestThe server cannot process the request due to a client error — malfor…401UnauthorizedAuthentication is required and has failed or not been provided. You …403ForbiddenYou are authenticated but do not have permission to access this reso…404Not FoundThe server cannot find the requested resource. The URL is valid but …409ConflictThe request conflicts with the current state of the resource (e.g. a…422Unprocessable EntityThe request was well-formed but the server could not process it due …429Too Many RequestsThe client has sent too many requests in a given time — rate limitin…500Internal Server ErrorA generic, unexpected error occurred on the server. The catch-all wh…502Bad GatewayThe server, acting as a gateway/proxy, got an invalid response from …503Service UnavailableThe server is temporarily unable to handle the request — overloaded …504Gateway TimeoutThe gateway/proxy did not get a response from the upstream server in…

1xx Informational

Request received, continuing process.

100ContinueThe server has received the request headers and the client should proceed to send the request body.101Switching ProtocolsThe server is switching protocols as requested by the client (e.g. upgrading to WebSocket).

2xx Success

The request was successfully received and processed.

200OKThe request succeeded. The meaning of success depends on the HTTP method (GET returns the resource, POST returns the result).201CreatedThe request succeeded and a new resource was created as a result. Commonly the response to a POST.202AcceptedThe request has been accepted for processing, but the processing is not complete (asynchronous work).204No ContentThe request succeeded but there is no content to return in the response body.

3xx Redirection

Further action is needed to complete the request.

301Moved PermanentlyThe resource has been permanently moved to a new URL. Search engines transfer ranking to the new URL.302FoundThe resource is temporarily at a different URL. The original URL should keep being used in future.304Not ModifiedThe cached version of the resource is still valid, so the server returns no body (saves bandwidth).307Temporary RedirectLike 302 but the HTTP method and body MUST NOT be changed when redirecting.308Permanent RedirectLike 301 but the method and body MUST NOT be changed.

4xx Client Error

The request has bad syntax or cannot be fulfilled.

400Bad RequestThe server cannot process the request due to a client error — malformed syntax, invalid JSON, or failed validation.401UnauthorizedAuthentication is required and has failed or not been provided. You are not logged in / token is invalid.403ForbiddenYou are authenticated but do not have permission to access this resource. Different from 401.404Not FoundThe server cannot find the requested resource. The URL is valid but the resource does not exist.405Method Not AllowedThe HTTP method is not supported for this resource (e.g. POST to a read-only endpoint).409ConflictThe request conflicts with the current state of the resource (e.g. a duplicate).410GoneThe resource was here but has been permanently removed and will not come back.422Unprocessable EntityThe request was well-formed but the server could not process it due to semantic (validation) errors.429Too Many RequestsThe client has sent too many requests in a given time — rate limiting has kicked in.

5xx Server Error

The server failed to fulfil a valid request.

500Internal Server ErrorA generic, unexpected error occurred on the server. The catch-all when nothing more specific fits.501Not ImplementedThe server does not support the functionality required to fulfil the request.502Bad GatewayThe server, acting as a gateway/proxy, got an invalid response from an upstream server.503Service UnavailableThe server is temporarily unable to handle the request — overloaded or down for maintenance.504Gateway TimeoutThe gateway/proxy did not get a response from the upstream server in time.505HTTP Version Not SupportedThe server does not support the HTTP protocol version used in the request.

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