Are unofficial codes listed?

We focus on commonly documented standard codes; vendor extensions may be missing.

HTTP Status Codes

Searchable reference for standard HTTP status codes.

What this tool does

Filter 1xx–5xx codes by category or search by code or phrase. Handy for debugging APIs and writing clients.

Class

Code	Reason	Notes
100	Continue	Client should continue
101	Switching Protocols	Protocol upgrade
102	Processing	WebDAV; still processing
103	Early Hints	Preload hints
200	OK	Success
201	Created	Resource created
202	Accepted	Accepted for async processing
203	Non-Authoritative Information	From transforming proxy
204	No Content	Success, no body
205	Reset Content	Client should reset document
206	Partial Content	Range request
207	Multi-Status	WebDAV mixed result
208	Already Reported	WebDAV
226	IM Used	Delta encoding
300	Multiple Choices	Redirect options
301	Moved Permanently	New URI
302	Found	Temporary redirect
303	See Other	GET to other URI
304	Not Modified	Cache valid
307	Temporary Redirect	Same method
308	Permanent Redirect	Same method
400	Bad Request	Malformed
401	Unauthorized	Auth required
402	Payment Required	Reserved
403	Forbidden	Not allowed
404	Not Found	Unknown resource
405	Method Not Allowed	Verb not supported
406	Not Acceptable	Cannot satisfy Accept
407	Proxy Authentication Required	Proxy auth
408	Request Timeout	Idle too long
409	Conflict	State conflict
410	Gone	Permanently removed
411	Length Required	Need Content-Length
412	Precondition Failed	ETag / If-* failed
413	Payload Too Large	Body too big
414	URI Too Long	URL too long
415	Unsupported Media Type	Wrong content type
416	Range Not Satisfiable	Bad range
417	Expectation Failed	Expect header failed
418	I'm a teapot	RFC 2324 / joke
421	Misdirected Request	Wrong server
422	Unprocessable Entity	Validation error
423	Locked	WebDAV
424	Failed Dependency	WebDAV
425	Too Early	Replay risk
426	Upgrade Required	Upgrade protocol
428	Precondition Required	Conditional required
429	Too Many Requests	Rate limit
431	Request Header Fields Too Large	Headers too big
451	Unavailable For Legal Reasons	Legal block
500	Internal Server Error	Generic server error
501	Not Implemented	Unsupported method
502	Bad Gateway	Upstream invalid
503	Service Unavailable	Maintenance / overload
504	Gateway Timeout	Upstream timeout
505	HTTP Version Not Supported	Version not supported
506	Variant Also Negotiates	Negotiation loop
507	Insufficient Storage	WebDAV
508	Loop Detected	WebDAV
510	Not Extended	Extension required
511	Network Authentication Required	Captive portal

Example input/output

Illustrative sample — your real inputs may look different.

Example input

Search: 429

Example output

429 Too Many Requests — client should back off / retry-after