Free SSL Certificate Expiry Monitor
Enter any domain to see exactly when its TLS certificate expires and how many days are left — instantly, with no signup. Then let Merlonix watch every client certificate for you, before the 47-day cliff bites.
How do I check when an SSL certificate expires?
Enter a domain above and Merlonix reads its live TLS certificate — the issuer, the valid-from and valid-to dates, the exact number of days until it expires, and every hostname the certificate covers. It is the same public certificate data a browser sees; no account or verification is needed.
What is the 47-day certificate cliff?
In 2025 the CA/Browser Forum voted to shorten the maximum TLS certificate lifespan in stages: from roughly 200 days today to 100 days in 2027 and 47 days in 2029. Shorter certificates are more secure, but they mean up to 8× more renewals per certificate every year. For anyone managing a portfolio of domains, a manual calendar reminder stops scaling well before 2029 — one missed renewal takes a site offline for every visitor.
How do I track SSL expiry across many client domains?
Run a one-off check above for a single domain, then claim the free Merlonix plan ($0, no credit card) to monitor up to three domains continuously, or start a trial to watch your whole portfolio. Merlonix re-checks every certificate on a schedule and alerts you 30 and 7 days before expiry — across every domain you or your clients depend on — so a renewal never slips through.
Does a one-time check protect me?
No — a one-time check is a snapshot of today. The certificate that matters is the one that lapses three weeks from now, after you've stopped looking. As certificate lifespans shrink toward 47 days, the only reliable protection is continuous monitoring with alerts ahead of each expiry, not a check you have to remember to repeat.