Cheat Sheets
HTTP Status Code Cheatsheet
Quick reference for common HTTP status codes grouped by class (100, 200, 300, 400, 500).
Search Status Codes
100xx
| Code | Detail | Common cause |
|---|---|---|
100 — Continue | Request received, continue. | Client should continue request (rarely used directly). |
101 — Switching Protocols | Protocol is switching as requested by client. | Websocket upgrade or protocol negotiation. |
200xx
| Code | Detail | Common cause |
|---|---|---|
200 — OK | Standard success response. | Request processed successfully. |
201 — Created | Resource created successfully. | POST resulted in new resource. |
202 — Accepted | Request accepted but not completed. | Async processing queued. |
204 — No Content | Successful but no body returned. | DELETE or successful update with no payload. |
300xx
| Code | Detail | Common cause |
|---|---|---|
301 — Moved Permanently | Resource moved to new URL. | URL changed; use new location. |
302 — Found | Temporary redirect. | Temporary resource relocation. |
304 — Not Modified | Cached copy is still valid. | Conditional GET with unchanged resource. |
400xx
| Code | Detail | Common cause |
|---|---|---|
400 — Bad Request | Malformed request syntax or invalid parameters. | Invalid JSON, missing fields, or bad query. |
401 — Unauthorized | Authentication required or failed. | Missing/invalid auth token. |
403 — Forbidden | Authenticated but not allowed. | Insufficient permissions. |
404 — Not Found | Requested resource not found. | Wrong URL or deleted resource. |
405 — Method Not Allowed | HTTP method not supported for this resource. | Using POST on a read-only endpoint. |
408 — Request Timeout | Server timed out waiting for the request. | Slow client or dropped connection. |
409 — Conflict | Request could not be completed due to conflict. | Concurrent edits or duplicate resource. |
410 — Gone | Resource permanently removed. | Resource intentionally removed and no redirect. |
429 — Too Many Requests | Rate limit exceeded. | Client exceeded request quota. |
500xx
| Code | Detail | Common cause |
|---|---|---|
500 — Internal Server Error | Generic server error. | Unhandled exception or misconfiguration. |
502 — Bad Gateway | Invalid response from upstream server. | Upstream service unavailable or misbehaving. |
503 — Service Unavailable | Server currently unable to handle request. | Maintenance or overloaded service. |
504 — Gateway Timeout | Upstream service timed out. | Slow upstream dependency. |