HTTP Status Code Reference Atlas

Status Code 000 (or 0) indicates a browser network failure, CORS preflight block, DNS lookup failure, or broken connection before receiving any response headers from the server.

Server has received request headers and client should proceed to send the request body.

Requester has asked server to switch protocols (e.g. WebSocket handshake).

Standard response for successful HTTP requests.

Request fulfilled, resulting in the creation of a new resource.

Request has been accepted for asynchronous processing, but processing has not completed.

Server successfully processed request, but is not returning any content in response body.

Server delivering only part of the resource due to a range header sent by client (useful for video streaming).

This and all future requests should be directed to the given URI.

Resource temporarily resides under a different URI.

Resource has not been modified since last requested (client cache valid).

Request should be repeated with another URI while retaining original HTTP method.

Request and all future requests should be repeated using another URI with same HTTP method.

Server cannot process request due to client syntax error or malformed payload.

Authentication is required and has failed or has not yet been provided.

Request was valid, but server is refusing action due to insufficient permissions.

Requested resource could not be found on the server.

Request method (GET, POST, PUT, DELETE) is not supported for requested resource.

Request could not be processed due to a conflict with current state of resource (e.g. duplicate username/email, resource already exists).

URI provided was too long for server to process (commonly occurs when passing giant query strings in GET requests).

Non-standard status code used by frameworks like Laravel to indicate that a CSRF token has expired or session timed out.

Unofficial response code used historically by Twitter API v1 when client was rate limited ("Enhance Your Calm") or Spring Framework method failure.

Request was well-formed but was unable to be followed due to semantic validation errors.

User has sent too many requests in a given amount of time (rate limiting).

Unofficial vendor extension status code used by proprietary API microservices and WebDAV extensions.

Unofficial custom HTTP response status code used by specialized API implementations to signal missing user consent or policy acceptance.

Generic error message when an unexpected condition was encountered on server.

Server either does not recognize request method, or lacks ability to fulfill request.

Server received an invalid response from upstream server while acting as gateway.

Server is currently unable to handle request due to temporary overload or maintenance.

Server acting as gateway did not receive timely response from upstream server.

Unofficial 5xx series status code used by custom server applications, gateway proxies, and backend microservices.