Enter a domain to inspect the certificate its server presents: issuer, validity dates, covered host names, key strength, TLS version, cipher and certificate chain. Each finding explains what is wrong and how to fix it.
SSL Certificate Checker
Check any site's SSL/TLS certificate: expiry, issuer, chain, TLS version and host-name match, graded A to F.
Check any website's SSL/TLS certificate
See who issued the certificate, when it expires, which names it covers, the TLS version and the chain, graded A to F with fixes for any problem.
About the ssl certificate checker
Check the SSL/TLS certificate of any website: who issued it, when it expires, which host names it covers, which TLS version and cipher the server uses, and whether the chain is complete. It is an SSL certificate checker that grades the result from A to F and tells you how to fix any problem.
Also searched as: SSL certificate checker · TLS certificate checker · SSL checker · certificate expiry checker · check SSL certificate online · HTTPS certificate test · SSL certificate chain checker
What the check looks at
The tool connects to the server on the port you choose, completes a real TLS handshake and reads the certificate the server presents. It checks that a public certificate authority issued it, that the name you entered is covered, how many days remain, the key strength, the negotiated TLS version and cipher, and the chain of intermediate certificates.
Why certificates fail
The usual causes are an expired certificate (auto-renewal stopped), a name mismatch (the certificate covers example.com but not www.example.com), a missing intermediate certificate (works in some browsers and fails in others) and old TLS versions. Each finding shows what was found and how to fix it.
Beyond websites
Use the port selector to test mail and directory services as well: SMTPS (465), submission (587), IMAPS (993), POP3S (995) and LDAPS (636). An expired mail certificate is a common reason for sudden delivery or login errors.
How this tool works and how to read the results
Frequently asked questions
How do I check when my SSL certificate expires?
Enter the domain and press Check certificate. The result shows the exact expiry date and the number of days left, with a warning below 30 days.
Why does my site say the certificate is not trusted?
Either the certificate is self-signed, the issuing authority is not public, the intermediate certificate is missing from the chain, or the certificate does not cover the host name you are using.
What is a certificate chain?
Your certificate is signed by an intermediate authority, which is signed by a root that browsers already trust. The server must send the intermediate too. If it does not, some clients cannot build the chain and show an error.
Which TLS version should I use?
TLS 1.3 where possible and TLS 1.2 as the minimum. TLS 1.0 and 1.1 are deprecated and should be disabled.