HTTP/1.1 has 41 defined response (status) codes.
- 100 Continue
- 101 Switching protocols
- 200 OK
- 201 Created
- 202 Accepted
- 203 Non-authoritative information
- 204 No content
- 205 Reset content
- 206 Partial content
- 300 Multiple choices
- 301 Moved permanently
- 302 Found
- 303 See other
- 304 Not modified
- 305 Use proxy
- 306 (Reserved code, no longer used)
- 307 Temporary redirect
- 400 Bad request
- 401 Unauthorised
- 402 Payment required (Reserved code, for future use)
- 403 Forbidden
- 404 Not found
- 405 Method not allowed
- 406 Not acceptable
- 407 Proxy authentication required
- 408 Request timeout
- 409 Conflict
- 410 Gone
- 411 Length required
- 412 Precondition failed
- 413 Request entity too large
- 414 Request-URI too long
- 415 Unsupported media type
- 416 Request range not satisfiable
- 417 Expectation failed
- 500 Internal server error
- 501 Not implemented
- 502 Bad gateway
- 503 Service unavailable
- 504 Gateway timeout
- 505 HTTP version not supported
O’Reilly And Associates produce a great pocket reference to the HTTP protocol:
- HTTP Pocket Reference at Amazon.com
- HTTP Pocket Reference at Amazon.co.uk (for British readers)
They also produce a much larger book on the subject:
- HTTP: The Definitive Guide at Amazon.com
- HTTP: The Definitive Guide at Amazon.co.uk (for British readers)