SSL Checker
Check a website's SSL certificate details and expiry.
âšī¸ Connects on port 443 and inspects the certificate the server presents - no data is fetched from the site itself.
How SSL Checker works
How does this tool work?
After confirming the hostname resolves to a public address, the checker opens a raw TLS connection to port 443 with SNI set to your hostname and captures the certificate the server presents via stream_socket_client. It then parses that certificate with openssl_x509_parse to read the subject, issuer, validity dates, and Subject Alternative Names, with peer verification deliberately turned off since the goal is to inspect whatever certificate is served, not to judge whether it should be trusted.
When would I use this?
Useful for checking how many days remain before a certificate expires, confirming which domains a cert covers through its SANs, or verifying the issuing CA right after installing a new certificate.
Does it check anything else on the site?
No page content is fetched - only the TLS handshake and certificate exchange happen, so this works even against sites that block bots or return errors on normal requests. It only checks port 443, so a site serving TLS on a non-standard port, or one that only answers on plain HTTP, will show a connection failure here rather than certificate details.