Common status codes — see RFC 9110 for the full registry.
| Code | Name | Description |
|---|---|---|
| 100 | Continue | Client should continue with request. |
| 101 | Switching Protocols | Protocol upgrade (e.g. WebSocket). |
| 102 | Processing | Server processing; no response yet. |
| 200 | OK | Request succeeded. |
| 201 | Created | Resource created. |
| 204 | No Content | Success with empty body. |
| 301 | Moved Permanently | Resource moved; update bookmarks. |
| 302 | Found | Temporary redirect (often POST→GET). |
| 304 | Not Modified | Cached copy still valid. |
| 400 | Bad Request | Malformed or invalid request. |
| 401 | Unauthorized | Authentication required. |
| 403 | Forbidden | Authenticated but not allowed. |
| 404 | Not Found | Resource does not exist. |
| 405 | Method Not Allowed | HTTP method not supported for route. |
| 408 | Request Timeout | Server waited too long for client. |
| 409 | Conflict | State conflict with current resource. |
| 413 | Payload Too Large | Request body exceeds limit. |
| 429 | Too Many Requests | Rate limited. |
| 500 | Internal Server Error | Unexpected server failure. |
| 502 | Bad Gateway | Upstream server returned invalid response. |
| 503 | Service Unavailable | Temporarily overloaded or maintenance. |
| 504 | Gateway Timeout | Upstream server did not respond in time. |