SSL certificate checker
Enter a domain to see its HTTPS certificate: issuer, expiry date, covered names and whether the name matches.
Run the check
What this checks
- Connects to
- Port 443 of the domain, from our server
- Shows
- Trust result, days left, issuer, subject, names, protocol, chain
- Does not do
- Revocation checks or scans of other ports
Free to use, up to 6 checks a minute and 60 a day from one address. The check runs on our server and the result is not stored by this tool.
Where to find it
The certificate is whatever the web server presents to a browser. Your host or certificate authority manages renewals.
Common mistakes
- Checking example.com when the site uses www.example.com. The certificate must cover the name visitors use.
- Forgetting that a certificate can expire while the site still loads for people who click through a warning.
Questions
What does trusted mean here?
The certificate chain validates against the certificate authority list built into our server runtime and covers the hostname you entered. Browsers can differ in edge cases.
Can it check an IP address or another port?
No. Only public domain names on port 443 are accepted.
Why can a check fail for a working site?
The server may be slow, block our server address, or only answer on a different name. The page shows what went wrong.