HTTP Status & Ports Reference

Searchable HTTP status codes and common TCP/UDP ports — keyboard-first.

100% client-side · no data leaves this device

61 status codes

Code	Name	Description
100	Continue	Client may continue the request; often used before uploading a large body.
101	Switching Protocols	Server agrees to upgrade the connection (e.g. to WebSocket).
102	Processing	Request accepted but still being processed; prevents client timeout.
103	Early Hints	Preload hints sent before the final response (Link headers).
200	OK	Request succeeded; the standard success response.
201	Created	Resource created successfully, usually after POST.
202	Accepted	Request accepted for processing but not yet completed.
203	Non-Authoritative Information	Success but payload may be from a transformed or cached copy.
204	No Content	Success with no body — common for DELETE or updates.
205	Reset Content	Success; client should reset the document view.
206	Partial Content	Partial GET response for a byte-range request.
207	Multi-Status	Multiple independent status codes in one response (often XML).
208	Already Reported	Members of a DAV binding were already enumerated.
226	IM Used	Server fulfilled GET using instance-manipulations (delta encoding).
300	Multiple Choices	Several representations available; client should choose one.
301	Moved Permanently	Resource moved permanently; update bookmarks and links.
302	Found	Temporary redirect; method may change to GET on follow-up.
303	See Other	Redirect to a different URI; follow-up should use GET.
304	Not Modified	Cached copy is still valid; no body returned.
307	Temporary Redirect	Temporary redirect; method and body must not change.
308	Permanent Redirect	Permanent redirect; method and body must not change.
400	Bad Request	Malformed syntax or invalid parameters.
401	Unauthorized	Authentication required or failed.
402	Payment Required	Reserved for future use; occasionally used by payment APIs.
403	Forbidden	Server understood but refuses to authorize the request.
404	Not Found	No matching resource at the requested URI.
405	Method Not Allowed	HTTP method not supported for this resource.
406	Not Acceptable	Cannot produce a response matching Accept headers.
407	Proxy Authentication Required	Client must authenticate with the proxy first.
408	Request Timeout	Server timed out waiting for the client to send the request.
409	Conflict	Request conflicts with current state (e.g. duplicate resource).
410	Gone	Resource permanently removed with no forwarding address.
411	Length Required	Content-Length header required but missing.
412	Precondition Failed	Precondition header (If-Match, etc.) evaluated to false.
413	Payload Too Large	Request body exceeds server limit.
414	URI Too Long	Request URI exceeds what the server is willing to parse.
415	Unsupported Media Type	Content-Type not supported for this endpoint.
416	Range Not Satisfiable	Requested byte range cannot be satisfied.
417	Expectation Failed	Expect request header requirement could not be met.
418	I'm a teapot	April Fools' RFC 2324 joke; sometimes used for non-standard errors.
421	Misdirected Request	Request sent to a server unable to produce a response.
422	Unprocessable Entity	Well-formed JSON/XML but semantic validation failed.
423	Locked	Resource is locked (WebDAV).
424	Failed Dependency	Action failed because a dependent action failed.
425	Too Early	Server unwilling to risk processing a replayable request.
426	Upgrade Required	Client must upgrade to a different protocol (TLS, WebSocket).
428	Precondition Required	Origin requires conditional requests to prevent lost updates.
429	Too Many Requests	Rate limit exceeded; check Retry-After header.
431	Request Header Fields Too Large	Total size of request headers exceeds server limit.
451	Unavailable For Legal Reasons	Access denied for legal reasons (censorship, DMCA).
500	Internal Server Error	Unexpected server failure; check logs.
501	Not Implemented	Server does not support the functionality required.
502	Bad Gateway	Upstream server returned an invalid response.
503	Service Unavailable	Server overloaded or down for maintenance.
504	Gateway Timeout	Upstream server did not respond in time.
505	HTTP Version Not Supported	Server does not support the request HTTP version.
506	Variant Also Negotiates	Circular reference during transparent content negotiation.
507	Insufficient Storage	Unable to store the representation needed (WebDAV).
508	Loop Detected	Infinite loop detected while processing (WebDAV).
510	Not Extended	Further extensions to the request are required.
511	Network Authentication Required	Client must authenticate to the network (captive portal).