SSL Certificate Expiring (90 Days)

What This Check Does

The SSL Certificate Expiring (90 Days) check detects when your domain's SSL/TLS certificate is set to expire within the next 90 days. DNS Spy connects to your domain over HTTPS, retrieves the certificate, and compares the expiration date against the current date. If fewer than 90 days remain, this check triggers an early warning alert.

This is the earliest of three expiration warning thresholds DNS Spy monitors, giving you maximum lead time to renew before any service disruption occurs.

Why It Matters

An expired SSL certificate causes browsers to display security warnings, blocking visitors from reaching your site. For businesses, this translates directly to lost revenue, damaged customer trust, and potential SLA violations. The 90-day window gives your team ample time to initiate the renewal process, obtain a new certificate from your certificate authority, install it, and verify the configuration — without any last-minute scrambling.

Many certificate authorities, including Let's Encrypt, issue certificates with 90-day lifetimes. Monitoring at this threshold ensures you catch renewals before automated tools miss them or before manual processes fall through the cracks.

Good vs. Bad Configuration

Bad Configuration

Your certificate for example.com expires in 75 days and no renewal has been initiated. Auto-renewal is not configured, and the renewal reminder emails went to an unmonitored inbox.

Good Configuration

Your certificate for example.com expires in 75 days, but auto-renewal is configured via Certbot or your certificate provider's dashboard. A DNS Spy alert confirms the renewal cycle is working as expected.

How DNS Spy Monitors This

DNS Spy checks your SSL certificate expiration date during each monitoring cycle. When fewer than 90 days remain, an alert is generated and delivered via your configured notification channels — email, Slack, or webhook. DNS Spy continues monitoring and will escalate to the 30-day and 7-day warning checks as the deadline approaches.