StillOnline?

SSL certificate expiry monitoring for your SaaS status page

An expired TLS certificate takes down HTTPS before your app logic fails. Customers see browser warnings; API clients get handshake errors. Uptime on /health goes red at the same moment — but advance warning before expiry saves weekend renewals.

StillOnline offers dedicated SSL certificate checks (hourly probe, expiry alerts) alongside HTTP uptime checks. This guide covers what each check type does, how cert outages appear on your status page, and plan limits on Free (one URL check per project).

Quick answer

Add an SSL check in StillOnline for your production hostname — probes run every one hour (fixed interval), with owner alerts when expiry is within your configured window (default 14 days). An HTTP check on the same host also fails when the cert is invalid, but without early expiry warning. Free allows one check per project — choose HTTP uptime or SSL early warning until Pro adds up to 10 checks. Publish cert-related downtime on a Payments or API component, not a vague “everything down” banner.

HTTP check vs SSL check

Check typeInterval (typical)DetectsBest for
HTTP GET /health5 min (Free)Site unreachable, bad cert at handshakeCustomer-visible uptime
SSL certificate1 hour (fixed)Expiry date, chain issues before traffic diesRenewal reminders

Per RFC 8446, TLS must succeed before HTTP — a dead cert means both checks fail once expired.

When the cert expires — status page messaging

  1. Before expiry — SSL check alerts you (email, Telegram, Slack); status page can stay green if HTTP still works.
  2. At expiry — HTTP check goes DOWN; open an incident on the component customers hit (usually API or App).
  3. After renew — wait for two successful probes before resolving; CDN caches may lag.

Link subscribers to stillonline.tech/s/demo — not Twitter alone. See public status page guide.

Setup in StillOnline

  1. App → project → New check → SSL.
  2. Enter https://api.yourproduct.com (hostname matters; path optional).
  3. Set alert threshold (days before expiry) if the UI exposes it — default 14 days.
  4. On Free, if you already use the single slot for HTTP, upgrade to Pro for both — pricing.

HTTP check on the same host:

curl -vI https://api.yourproduct.com/health 2>&1 | grep -i expire

Use openssl s_client for local debugging; StillOnline probes from its worker network.

Indie pitfalls

IssueMitigation
Cert on CDN, origin forgottenMonitor customer-facing hostname StillOnline users hit
Auto-renew failed (Let’s Encrypt)SSL check + calendar reminder
Wildcard renewed, leaf missedCheck the exact API host
Only monitoring marketing wwwAPI subdomain may expire separately — API-only checks

FAQ

Does StillOnline SSL monitoring replace Certbot reminders?

It complements them. StillOnline alerts owners through your configured channels; you still renew at the CA or CDN.

Will an SSL check alone keep my status page green when HTTPS is broken?

No. When the cert is invalid, HTTP checks fail too. SSL check adds early expiry warning while HTTPS still works.

Further reading