Quiz Entry - updated: 2026.10.15
What do the HTTP status codes 200, 201, 400, 401, 403 and 404 mean?
- 200 OK: the request worked (typical for GET or POST).
- 201 Created: a new resource was created.
- 400 Bad Request: the client sent something wrong.
- 401 Unauthorized: not authenticated.
- 403 Forbidden: authenticated but not allowed.
- 404 Not Found: the URL doesn't exist or is hidden.
The first digit tells you the category before you even read the rest:
| Range | Meaning | Codes |
|---|---|---|
| 2xx | Success | 200 OK: data exchanged with GET or POST. 201 Created: a resource was created through the API |
| 4xx | Client error: you got something wrong | 400: malformed request (bad JSON, missing field). 401: no valid credentials or token. 403: credentials valid but no permission. 404: no such resource at that URL |
(5xx codes, not in this list, mean the server failed.)
For automation, the status code is the first thing a script checks. 2xx means carry on, 4xx means the request itself must be fixed. Retrying a 4xx unchanged won't help.
Go deeper:
HTTP response status codes — MDN — every code with its meaning, grouped by class.- List of HTTP status codes — Wikipedia — including vendor-specific and unofficial codes.