Free IT & Cyber Security Tool

SSL Certificate Checker

Check whether a website SSL certificate is valid, who issued it, and when it expires.

Check SSL Certificate

Enter the domain only. The checker connects to port 443 and reads the certificate details.

Result

Enter a domain to check its certificate.

FAQs

Why does SSL expiry matter?

Expired certificates trigger browser warnings and can stop customers from trusting or accessing your website.

What if the checker cannot connect?

The domain may not support HTTPS, port 443 may be blocked, or the hosting server may be refusing the connection.

How early should certificates be renewed?

Many certificates auto-renew, but it is sensible to investigate anything with less than 30 days remaining.

Can MDS help with SSL issues?

Yes. MDS can review hosting, DNS, redirects, certificate installation and renewal problems.

Need help with your IT or cyber security?

Contact MDS for practical support with Microsoft 365, DNS, email security, SSL, domains, networks and business technology.