TLS certificate check

Certificate Checker

Check whether a public website has a TLS certificate that is present, in date, and issued for the hostname you entered.

Public 443 only CK Cyber connects to the public hostname on HTTPS port 443 to read the TLS certificate. Internal names, private IPs, custom ports, paths, tokens, and localhost are blocked.

I will check only public websites I own, operate, or am allowed to review. I understand CK Cyber makes a server-side TLS connection to the hostname I enter and is not responsible for my use of this tool.

Website Hostname

Enter a public domain such as ckcyber.com or www.example.com. The app ignores protocol and path.

Public hostname Do not enter private portals, reset links, customer URLs, IP addresses, or internal hostnames.

Check the acknowledgement box to begin.

Certificate Details

Issuer, subject, SANs, validity dates, fingerprint, TLS handshake details, and simple findings.

Enter a public hostname to check its TLS certificate.

What This Checks

Certificate presence, hostname match, expiration, issuer and subject details, SAN entries, SHA-256 fingerprint, chain count, and negotiated TLS/cipher metadata when available.

What It Does Not Check

It does not scan ports, crawl pages, test every cipher, test every protocol version, verify revocation at CA scale, or replace SSL Labs or a full TLS assessment.

Privacy And Responsibility

The entered hostname is sent to CK Cyber's certificate endpoint so the server can connect to that public host on 443. Do not submit private, internal, or sensitive hostnames.