SSL Expiry Monitoring
Why this matters
An expired TLS certificate makes a perfectly healthy server look completely broken — browsers block access outright with a hard security warning. A normal uptime check won't catch this in advance; it only notices once the outage has already started. SSL Expiry Monitoring checks the certificate itself, ahead of time.
How it works
Every HTTPS monitor gets its certificate checked automatically, roughly once a day — nothing to turn on or configure. HTTP-only monitors have no certificate to check, so nothing appears for them.
Where to see it
Open any HTTPS monitor's detail page — you'll see how many days remain before its certificate expires. This is visible on every plan, including free.
When you get alerted
The warning window scales with the certificate's own lifetime rather than using one fixed number of days for every certificate: it's roughly a third of the certificate's total validity period, with a 3-day minimum even for very short-lived certificates. A typical one-year certificate gets warned about roughly 4 months out; a 90-day certificate gets warned about roughly a month out. Actual alert notifications (to your configured channels) are a Starter-plan-and-above feature — visibility on the monitor page is free on every plan.
If you renew the certificate
Nothing to dismiss manually — the next check simply sees the new certificate's expiry date, the warning clears on its own, and you'd get warned again ahead of the new one's own expiry.