Free SSL & DNS Checker
Enter any domain to see its TLS certificate expiry, issuer, and live DNS records — instantly, with no signup. Then let Merlonix watch it for you around the clock.
What does the free SSL & DNS checker check?
The checker reads the same public signals Merlonix monitors continuously: your TLS certificate's issuer, validity window, days until expiry, and the hostnames it covers; the domain's A/AAAA, MX, and NS records; and the domain's registration expiry. Everything here is public information — no account or verification needed.
Why does SSL and DNS health matter?
An expired certificate takes a site offline for every visitor and erodes trust instantly. DNS drift can silently reroute traffic or break email, and a lapsed domain registration takes everything down at once. A one-time check tells you where things stand today; continuous monitoring is what catches the expiry that's 21 days out — before it becomes an incident.
How do I monitor a domain continuously?
Merlonix watches SSL expiry, DNS configuration, domain registration, and uptime across every domain you (or your clients) depend on, and alerts you the moment something changes. Run a check above, then claim the free plan ($0, no credit card) to keep one domain monitored, or start a 14-day trial for the full workspace.
Related reading
- Domain-hijack monitoring — get paged the moment your transfer lock is removed
- Continuous DNSSEC & DANE monitoring — get paged when your zone goes unsigned
- TLS posture monitoring — get paged when your cipher, protocol, or chain degrades
- A client domain expired — what to do (and how to prevent it)
- Domain-expiry monitoring for agencies
- How to set up SSL monitoring for all client domains in 30 minutes
Monitor SSL & DNS continuously — not just once
A one-off check tells you where things stand today. Merlonix re-checks certificate expiry, DNS records, and domain registration on a schedule and alerts you before an expiry 21 days out becomes an incident.
No credit card required.