A comprehensive reference of all standard HTTP response status codes, organized by category and including detailed explanations.
The server acknowledges the initial request and instructs the client to continue with the rest of the request.
The server agrees to switch to a different protocol as requested via the Upgrade header.
Indicates that the server has received and is processing the request, but no response is available yet.
Used to return preliminary headers before the final response, often for improving performance.
The request succeeded. Response content depends on method (GET returns resource, POST returns result, etc.).
A new resource was successfully created.
The request is accepted for processing, but not guaranteed to complete.
Returned metadata differs from the origin server’s but is collected from a local or third-party copy.
The request succeeded but no content is returned.
Instructs the client to reset the document view.
The server returns only part of the resource, as requested with range headers.
Multiple resource statuses returned.
Prevents repeated listing of the same internal members.
Indicates the server applied instance manipulations to the resource.
Multiple representation options available.
Resource permanently redirected to a new URI.
Temporary redirection.
Client should fetch the resource via GET at another URI.
Resource not changed; client can use cached version.
Indicates the resource must be accessed via a proxy.
No longer used.
Same as 302 but method consistency must be maintained.
Same as 301 but method consistency must be maintained.
Malformed request; server cannot process.
Authentication required.
Reserved; used for digital payment systems.
Request understood but refused.
Resource not found.
HTTP method not supported for resource.
Client’s Accept headers cannot be satisfied.
Client must authenticate with the proxy.
Server timed out waiting for client.
Request conflicts with current resource state.
Resource permanently removed.
Content-Length header missing.
Preconditions (If-* headers) not met.
Request body too large.
URI supplied is too long to be processed.
Content type not supported.
Requested range cannot be met.
Expectation from Expect header cannot be met.
Easter egg from HTCPCP protocol.
Request sent to the wrong server.
Well-formed but semantically invalid.
Resource is locked.
Previous request failure affects this one.
Server unwilling to risk replay attacks.
Client must switch protocol.
Server requires conditional requests.
Client sent too many requests (rate-limiting).
Headers too large.
Access restricted by legal demand.
Generic server error.
Server lacks capability to fulfill method.
Invalid response from upstream server.
Server temporarily overloaded or down.
Upstream server failed to respond.
Server does not support requested HTTP version.
Content negotiation configuration error.
Server cannot store resource.
Infinite loop detected while processing.
Further extensions required.
Client must authenticate to gain network access.