Test an SSL Certificate
Test a domain's SSL/TLS certificate — confirm it is installed correctly, trusted, and not expired.
What this SSL test checks
The test performs a real TLS handshake with the server and inspects the certificate it returns: the negotiated protocol, the issuer and validity window, the covered hostnames, and whether the chain is trusted. It is the same handshake a browser performs, so the result reflects what real visitors experience.
Common SSL certificate problems
Tests frequently surface expired certificates, self-signed or untrusted chains, hostname mismatches (the certificate does not cover the domain you visited), and incomplete intermediate chains. Each of these can trigger browser warnings even when HTTPS appears to "work" locally.
Frequently asked questions
Does this test private or internal servers?
No. The test only works against publicly reachable domains on port 443.
Will it detect an untrusted or self-signed certificate?
Yes — the result clearly flags whether the certificate chain is trusted by standard browsers.
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