SSL
SSL Certificate Checker
Check the validity, expiry date and certificate chain of any domain's SSL certificate.
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This check runs from the Backserver server with a real TLS connection to the target domain; your domain is never sent to a third party. Connections to internal or local-network addresses are blocked.
ABOUT
Check a domain’s SSL/TLS certificate: expiry, issuer and chain
A surprise certificate expiry is one of the most common causes of outages. This tool connects to your domain and shows the expiry date, issuer, SAN names and the full certificate chain so you can spot problems before browsers start warning. It needs a server-side connection to the host you enter, and only that hostname is processed.
HOW TO
How to use it
- Enter the domain without
https://. - Press check and wait for the result.
- Review the expiry date, SAN list and whether the chain is complete.
FAQ
Frequently asked questions
Why does the browser reject a certificate whose dates are fine?
Usually the chain is incomplete (the intermediate certificate is not served) or the hostname is missing from the SAN list.
How early should I renew?
For 90-day Let’s Encrypt certificates, automatic renewal about 30 days before expiry is common.