HTTP Status Codes Reference
Interactive guide to all standard 1xx–5xx HTTP response status codes and Cloudflare edge errors.
Initial request received, client should continue with request body.
Server agrees to switch protocols (e.g., Upgrade to WebSocket).
Standard response for successful HTTP requests with a response body.
Request succeeded and led to the creation of a new resource (POST / PUT).
Request succeeded but returns no response body (common for DELETE / PATCH).
Delivering part of the resource due to Range header sent by client (video streaming).
The resource has permanently moved to a new URL. Search engines transfer SEO link equity.
Temporary redirect. Search engines do not transfer link equity.
Cached version is still fresh according to ETag / If-Modified-Since headers.
Temporary redirect where the HTTP method (POST, PUT) must NOT change to GET.
Permanent redirect preserving the original HTTP method (POST stays POST).
Server cannot process request due to malformed syntax, invalid JSON, or missing parameters.
Authentication is required and has either failed or has not yet been provided.
Client identity is known, but the client does not have permission to access the resource.
Server cannot find the requested resource. Endpoint URL may be mistyped.
HTTP method used is not supported by the target resource (e.g. POST on a GET-only route).
Server timed out waiting for the client to complete sending the request.
Rate limit exceeded. Client has sent too many requests in a given time window.
Generic catch-all error indicating unhandled exception or crash in server application code.
Reverse proxy (Nginx, Cloudflare) received an invalid response from upstream server.
Server is overloaded, down for maintenance, or scaling capacity.
Reverse proxy or load balancer timed out waiting for upstream server to respond.
Cloudflare proxy received an empty or unparseable response from the origin server.
Origin server refused the TCP connection from Cloudflare's edge IP addresses.
TCP handshake between Cloudflare and origin server timed out.
Cloudflare connected, but origin did not send HTTP response within 100 seconds.