HTTP Status Codes Cheat Sheet

Complete HTTP status code reference. 1xx informational, 2xx success, 3xx redirection, 4xx client errors, 5xx server errors — with clear explanations.

1xx — Informational 2xx — Success 3xx — Redirection 4xx — Client Errors 5xx — Server Errors

1xx — Informational

100 Continue Server received headers, client should send body
101 Switching Protocols Server is switching to a different protocol (e.g., WebSocket)
103 Early Hints Preload resources while server prepares response

2xx — Success

200 OK Request succeeded — standard success response
201 Created Resource created successfully (POST/PUT)
204 No Content Success but no response body (DELETE)
206 Partial Content Partial resource returned (Range header)

3xx — Redirection

301 Moved Permanently Resource moved permanently — update your URL
302 Found Temporary redirect — keep using original URL
304 Not Modified Cached version is still valid — use cache
307 Temporary Redirect Like 302, but keep the same HTTP method
308 Permanent Redirect Like 301, but keep the same HTTP method

4xx — Client Errors

400 Bad Request Malformed request syntax or invalid parameters
401 Unauthorized Authentication required — provide valid credentials
403 Forbidden Authenticated but not authorized for this resource
404 Not Found Resource does not exist at this URL
405 Method Not Allowed HTTP method not supported for this endpoint
408 Request Timeout Server timed out waiting for the request
409 Conflict Request conflicts with server state (e.g., duplicate)
422 Unprocessable Entity Valid syntax but semantic errors in the data
429 Too Many Requests Rate limited — slow down your requests

5xx — Server Errors

500 Internal Server Error Generic server error — something broke
502 Bad Gateway Server got invalid response from upstream server
503 Service Unavailable Server is down or overloaded — try again later
504 Gateway Timeout Upstream server didn't respond in time

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