Log in Get started free

Home / Learn / HTTP 404 Not Found

404 Failed check: alerts, never counted as downtime

HTTP 404 Not Found

The server answered normally, but the exact path being monitored no longer exists.

What it usually means

The server answered normally, but the exact path being monitored no longer exists. Usually a route that moved during a deploy.

What to check first

The route moved or was renamed in a deploy.
The monitor points at the final URL, not one that used to redirect.
For a status-code monitor on a page that is meant to 404, add 404 to the accepted status codes.

How ErrorDetector reports it

The target answered, so this is reported as a failed check, not downtime: the alert names the reason, the uptime percentage is untouched, and a recovery notice follows when the check passes again.

Caught by: httpkeywordapi monitors. Read about the incident management feature.

Get the cause, not a red dot

Ten monitors free, no card, no time limit. Every incident names the failure.

Start monitoring free

Other causes

DNS · DNS resolution failed (NXDOMAIN, no answer) REF · Connection refused TLS · TLS handshake failed (certificate error) RST · Connection reset by peer NET · Host unreachable (no route) T/O · Connection timed out RDR · Redirect loop (too many redirects) KEY · Keyword not found on the page SLOW · Response slower than the limit ASSERT · API response failed its body assertion BLK · Blocked by a firewall or bot filter 401 · HTTP 401 Unauthorized 403 · HTTP 403 Forbidden 429 · HTTP 429 Too Many Requests 500 · HTTP 500 Internal Server Error 502 · HTTP 502 Bad Gateway 503 · HTTP 503 Service Unavailable 504 · HTTP 504 Gateway Timeout