Updated 2026-09-28
Certificate expiry is one of the most common causes of a "surprise" outage — the site is otherwise fine, but the certificate quietly lapsed. Status checks certificate validity directly, and warns you well ahead of expiry so it never comes as a surprise.
How it works
Every https:// HTTP check verifies the
certificate as part of its normal request (verifyTls). You can also add a
standalone SSL check against a host and port (443 by default) purely to
track certificate health independent of any HTTP monitoring.
An SSL check that can't validate the certificate (invalid, expired, wrong host, or the connection fails outright) goes down, exactly like any other check — it opens an incident, sends your alerts, and counts toward that check's uptime percentage in reports and on status pages.
Expiry warnings
Separately from that up/down state, certificate expiry is also tracked against a set of thresholds — by default 30, 14, 7, and 1 days before expiry. Status sends a warning once per threshold as the expiry date approaches, so you get advance notice instead of finding out when the certificate has already lapsed. These advance warnings are informational — unlike an actual certificate failure above, a warning does not open an incident or count against uptime. See SSL and domain expiry warnings for how these warnings behave and how to adjust the thresholds.
When to use it
Any HTTPS endpoint you care about, especially certificates that renew manually rather than through automation — Status gives you a heads-up well ahead of the deadline instead of an unexpected TLS error.