Free · without registration
Check SSL Certificate for Free
Check your domain’s TLS connection and see if the certificate is accepted and when it expires. HTTP errors and certificate errors are presented separately.
Which domain do you want to check?
Checks the host entered via HTTPS on port 443. Path and parameters are omitted; redirects are not tracked.
Result of the certificate examination
- TLS test
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- Residual maturity
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- HTTP response
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- Tested host
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- Issued for
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- Exhibitors
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- Alternative Host Names (SAN)
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- Valid off
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- Valid until
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What does the SSL Checker check?
The checker establishes a TLS connection to the specified domain. The hostname and the certificate chain are checked against the certificate memory of the check server. Where available, the result shows issuers, alternative host names and validity period of the server certificate.
Today, TLS is used; the term SSL certificate is still common. This single check does not perform a full check of all TLS versions, cipher suites or block lists.
Targeting certificate errors
- Expired: Check renewal with the hoster, install a new certificate and then test again.
- The hostname is not correct: A certificate for another domain does not protect the entered host. Also check www and other subdomains.
- Incomplete chain: Control the installation of intermediate certificates in your hosting configuration.
- Not determined: Limit DNS, network, or firewall issues first. A failed retrieval does not prove an invalid certificate.
Why does the check not follow a forwarding?
The TLS connection is established before the HTTP forwarding. Therefore, a forwarding domain also needs a valid certificate. If the check only checked the destination, it could miss an error on the original host. Then they use it for guidance. HTTPS Checker.
Frequent questions
Is an HTTP error also a certificate error?
No. A page can still deliver 404 or 500 via a correctly tested TLS connection. The checker shows both results separately.
Why is the expiration date missing?
In the event of a failed connection or missing certificate information, the date cannot be determined. The checker then invents no remaining time.
Can I test a certificate for www separately?
Yes. Specify the exact host. www.example.de and example.de are checked as different hosts.