SSL/TLS Certificate Checker

Inspect the TLS certificate a site serves and check the expiry, hostname coverage, trust chain, signature and key strength. Enter the hostname you want to check.

What does this check?

An SSL/TLS certificate proves a website's identity and encrypts the traffic between it and your browser. This tool performs a live TLS handshake with the host and inspects the certificate it presents — whether it covers the hostname, when it expires, whether the server sends a complete trust chain, and whether the signature and key are strong enough for modern clients.

Why does a certificate fail?

The most common problems are an expired certificate, a name that does not match the hostname, a missing intermediate certificate (an incomplete chain), or a self-signed certificate that no browser trusts by default. Each of these is called out separately above so you know exactly what to fix.