HTTP status codes are responses from a server telling you what happened when a request was made.

🟦 1XX — Informational

Code Name Description
100 Continue Request headers received; client should continue sending body
101 Switching Protocols Server agrees to switch protocol (e.g., HTTP → WebSocket)
102 Processing Server is still processing the request
103 Early Hints Preload resources before full response

🟩 2XX — Success

Code Name Description
200 OK Request succeeded
201 Created New resource created
202 Accepted Request accepted but not processed yet
203 Non-Authoritative Information Response modified by proxy
204 No Content Success, no response body
205 Reset Content Client should reset view/form
206 Partial Content Partial resource returned (Range requests)
207 Multi-Status Multiple resource status (WebDAV)
208 Already Reported Avoid duplicate reporting (WebDAV)
226 IM Used Resource modified via instance manipulation

🟨 3XX — Redirection

Code Name Description
300 Multiple Choices Multiple resource options available
301 Moved Permanently Resource permanently moved
302 Found Temporary redirect
303 See Other Redirect using GET
304 Not Modified Use cached version
307 Temporary Redirect Same method, temporary redirect
308 Permanent Redirect Same method, permanent redirect

🟄 4XX — Client Errors

Code Name Description
400 Bad Request Invalid request syntax
401 Unauthorized Authentication required/failed
402 Payment Required Reserved (rarely used)
403 Forbidden Access denied
404 Not Found Resource not found
405 Method Not Allowed Method not supported
406 Not Acceptable No matching response format
407 Proxy Authentication Required Proxy auth needed
408 Request Timeout Request timed out
409 Conflict Request conflicts with resource
410 Gone Resource permanently removed
411 Length Required Missing Content-Length
412 Precondition Failed Request conditions not met
413 Payload Too Large Request too large
414 URI Too Long URI too long
415 Unsupported Media Type Format not supported
416 Range Not Satisfiable Invalid range request
417 Expectation Failed Expect header not met
418 I’m a Teapot Joke status code ā˜•
421 Misdirected Request Wrong server
422 Unprocessable Entity Semantic errors in request
423 Locked Resource locked
424 Failed Dependency Dependent request failed
425 Too Early Replay attack risk
426 Upgrade Required Must switch protocol
428 Precondition Required Conditional request needed
429 Too Many Requests Rate limited
431 Header Fields Too Large Headers too large
451 Unavailable for Legal Reasons Blocked due to law

🟪 5XX — Server Errors

Code Name Description
500 Internal Server Error Generic server failure
501 Not Implemented Feature not supported
502 Bad Gateway Invalid upstream response
503 Service Unavailable Server overloaded/maintenance
504 Gateway Timeout Upstream timeout
505 HTTP Version Not Supported Version not supported
506 Variant Also Negotiates Configuration error
507 Insufficient Storage Not enough storage
508 Loop Detected Infinite loop detected
510 Not Extended Extensions required
511 Network Authentication Required Network login required

Notes: