Checks port 443 by default. Public hosts only.

A Spot Check Is Not Monitoring

This checks one host, once, right now. Certificates expire on a schedule you will forget, and an expired cert takes the whole site down until someone notices. Generator Labs watches every certificate across your domains and internal hosts, then alerts you well before expiry, with the chain and hostname problems flagged before they become outages.

  • Continuous expiry, chain, and hostname checks
  • Alerts days or weeks before expiry, your choice
  • Public and internal CA certificates, with a REST API
  • Per-host pricing at $0.01/host/day

How to Check an SSL Certificate

Enter any hostname above and this SSL certificate checker connects to the host over TLS, reads the certificate the server actually presents, and reports what matters: the expiration date, how many days remain before it expires, whether the certificate covers the hostname you entered, the key type and size, and the full certificate chain. Because it verifies the live certificate rather than a cached copy, it also flags expired, self-signed, and hostname-mismatched certificates that a browser might quietly accept or that fail only on fresh clients.

Check an SSL Certificate's Expiration

The most common reason to check an SSL certificate is expiration. An expired certificate fails closed: browsers block the page and API clients refuse to connect. This checker shows the exact expiry date and the days remaining, so you can renew before it lapses. To catch every expiry automatically instead of checking by hand, use SSL certificate monitoring. Mid-renewal? See our guide to renewing an SSL certificate.