SSL Certificate Monitoring
An expired SSL certificate doesn’t just show a browser warning - on many setups it takes the site down entirely, breaks API integrations, and erodes trust with anyone who hits it. It’s also one of the easiest things to lose track of, because certificates are often provisioned once and forgotten, sometimes by whoever set up the server years ago.
Expirity monitors the live certificate on each domain, the same way a browser would see it, so you find out before a visitor does.
What Expirity checks
Section titled “What Expirity checks”On every check, Expirity connects directly to the domain over TLS and inspects the live certificate, capturing:
- Expiry date and validity window
- Issuer
- Subject Alternative Names (SANs)
- Key algorithm and key strength
- Certificate chain validity
- Fingerprint - used to detect when a certificate has been replaced, even before expiry
Plan differences
Section titled “Plan differences”| Starter | Pro / Agency | |
|---|---|---|
| Status badge, expiry date, days remaining | ✓ | ✓ |
| Issuer, validity window, chain status | - | ✓ |
| Key algorithm, key strength, SANs | - | ✓ |
Starter shows the essentials needed to know whether a certificate needs attention. Pro and Agency unlock full certificate detail for teams diagnosing chain or configuration issues, not just tracking expiry.
Alerts
Section titled “Alerts”SSL alerts use the same threshold system as expiry alerts - 30, 7, and 1 days before certificate expiry by default, customizable on Pro and Agency. Expirity also detects and alerts on:
- Status transitions - a certificate moving from valid to expiring to expired
- Issuer changes - a certificate replaced by a different certificate authority
- Renewal - when a certificate is replaced ahead of expiry, confirming the renewal succeeded
When a certificate shows as unknown
Section titled “When a certificate shows as unknown”If Expirity can’t establish a TLS connection to a domain - the server is unreachable, TLS isn’t configured, or the handshake fails - the certificate status shows as unknown rather than guessing. Click Check now to retry, or verify the domain is resolving correctly first if the issue persists.