HTTP Status Codes

Code	Name	Description
100	Continue	Client should continue with request
101	Switching Protocols	Server is switching protocols (e.g., to WebSocket)
103	Early Hints	Preload headers before final response

Code	Name	Description
200	OK	Standard success response
201	Created	Resource created (POST/PUT)
202	Accepted	Request accepted, processing async
204	No Content	Success with no response body (DELETE)
206	Partial Content	Range request fulfilled (video streaming)

Code	Name	Description
301	Moved Permanently	URL permanently changed — SEO juice transferred
302	Found (Temporary)	Temporary redirect — use for A/B testing
303	See Other	Redirect to GET after POST (PRG pattern)
304	Not Modified	Client cache is still valid
307	Temporary Redirect	Temporary, preserves HTTP method
308	Permanent Redirect	Permanent, preserves HTTP method

Code	Name	Description
400	Bad Request	Malformed request syntax or invalid parameters
401	Unauthorized	Authentication required (not authenticated)
403	Forbidden	Authenticated but not authorized
404	Not Found	Resource does not exist
405	Method Not Allowed	HTTP method not supported
408	Request Timeout	Server timed out waiting for request
409	Conflict	Resource state conflict (e.g., duplicate)
410	Gone	Resource permanently deleted
413	Payload Too Large	Request body exceeds server limit
422	Unprocessable Entity	Validation error (common in REST APIs)
429	Too Many Requests	Rate limit exceeded

Code	Name	Description
500	Internal Server Error	Generic server error — check logs
501	Not Implemented	Server doesn't support this feature
502	Bad Gateway	Upstream server returned invalid response
503	Service Unavailable	Server overloaded or under maintenance
504	Gateway Timeout	Upstream server did not respond in time
507	Insufficient Storage	Server ran out of storage
511	Network Auth Required	Captive portal (hotel/airport WiFi)

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