How to get an alert before your SSL certificate (or domain) expires

Updated 2026-11-03 · Small business, landlords and freelancers · by CyberMax

Short answer

Check the certificate the server actually serves (not the one you think you installed) and its expiry date, then set an alert 30, 7 and 1 day before. Do the same for the domain registration itself: a lapsed domain takes the site, email and certificate down together. Auto-renew helps, but a failed renewal is exactly what an alert catches.

Copy-paste code

See the expiry date of the certificate a server presents

# certificate expiry (notAfter) as served by the site
echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null \
  | openssl x509 -noout -enddate

# domain registration expiry from the registry (RDAP)
curl -s https://rdap.org/domain/example.com | jq -r '.events[] | select(.eventAction=="expiration") | .eventDate'

Good to know

Check every hostname you use (www, api, mail), not only the main domain: each can have its own certificate.

If renewal is automatic, an alert that arrives 7 days out means the automation failed; fix it then, not on the last day.

Lapsemoor: Domain and SSL expiry alerts before anything lapses

from $1.99/month

Lapsemoor checks your domains every day, both the registration expiry (RDAP) and the certificate the server really serves, and alerts 30, 7 and 1 day before. Free for 10 domains; Pro covers 100.

Get Lapsemoor: $1.99/month See what's inside Check your domains free

Secure checkout · 14-day fix-or-refund if it doesn't work as described (terms)

Questions

How long do SSL certificates last?

Public certificates now last well under a year (the industry limit is shrinking in steps), and many free certificates last 90 days, so they renew often.

Why also watch the domain?

If the domain registration lapses, the website, the email and the certificate all stop working.

Is there a free monitor?

Lapsemoor checks 10 domains a day for free and alerts by Telegram, browser notification or a private RSS feed.

Free: the Small Business Starter Kit

Bookkeeping and profit previews plus free invoice, rent receipt, margin and HACCP/allergen tools, then 5 short emails on margins, invoicing and checklists.