How SSL certificate monitoring works

SSL Monitor is an external HTTPS monitoring service: we connect to your public endpoints the same way a browser does, verify the TLS certificate, and email you when action is needed — without agents on your servers.

Enter your domain on the homepage — we'll start monitoring right after you sign up.
Sign up with your email (magic link) or Google account.
We monitor continuously whether your certificate is valid and track expiry dates.
Get email alerts in time when renewal is due, when a certificate has expired, or if we detect a problem.
Add more domains — 5 free, upgrade anytime on the pricing page.

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What we check on every SSL/TLS connection

Each monitoring run opens an HTTPS connection to your hostname (default port 443). We confirm that a certificate is presented, that it is currently valid, and when it will expire. If the handshake fails — wrong hostname, expired cert, or chain error — the check is marked as failed and you can be alerted.

This approach works for public websites, staging environments with open DNS, and API gateways, as long as the endpoint is reachable from the internet over TLS.

When you receive certificate expiry alerts

Email notifications are sent ahead of certificate expiration and when monitoring detects an outage-level TLS problem. That gives developers and IT teams time to renew with Let's Encrypt, a commercial CA, or your hosting provider before users see "Your connection is not private" in the browser.

Alerts are designed for operators who manage more than one domain — agencies, SaaS teams, and e-commerce sites that cannot afford silent certificate failures.

Who SSL Monitor is for

Developers shipping apps who want expiry reminders without building custom cron jobs.

Agencies managing client sites that need centralized HTTPS health visibility.

Small businesses that rely on HTTPS for trust and payments but lack a dedicated security team.

Ready to protect your domains? Start free SSL monitoring or compare plans on pricing.