Can I configure which HTTP status codes count as "up"?
Yes. By default, Oh Dear treats any status code in the 200-399 range as "up", and anything else as a failure. You can override this per monitor if your endpoint intentionally returns different codes.
Where to configure valid HTTP status codes
- Open the monitor.
- Go to Settings > Uptime check.
- Find Valid status codes.
- Enter the codes (or ranges) you consider "up".
Valid HTTP status code entries
- Exact codes:
200,201,204 - Wildcard ranges:
2*(all 2xx),3*(all 3xx),4*(all 4xx) - Multiple values:
200, 204, 302
A common pattern for monitoring an authenticated endpoint you expect to return 401 is to list 401 as a valid code. That way Oh Dear treats the "authentication required" response as proof the endpoint is reachable, without needing to send credentials.
HTTP status code configuration examples
- Healthcheck endpoint:
200(and only 200) - Auth-required API:
401, 403(the API is up if it rejects unauthenticated requests) - Redirect endpoint:
301, 302, 307, 308 - Relaxed monitoring:
2*, 3*(default, don't care what specifically it returns as long as it's success or redirect)
Combine with look-for-string for stronger signal
HTTP status codes are easy to fake. A server can return 200 OK on a "we're on fire" error page. For endpoints where correctness matters, combine the status-code check with a look-for-string assertion on a specific snippet you expect in the body. That way the check fails if either the code or the content is wrong.
More background on what each status code means: What are HTTP status codes?.
