How can you check when an SSL certificate expires?

Open the site’s certificate information from the browser and look for the validity dates. This shows the certificate currently served to that browser for the exact hostname. Check both the root domain and www, since different endpoints or servers can present different certificates.

External TLS checkers and command-line tools can display the expiration date, issuer, covered names, and chain. Test from outside the hosting network so you see the public certificate. A CDN may serve its own edge certificate while the origin server uses a separate certificate with a different renewal date.

Automated certificates are usually renewed before expiration, but renewal can fail when DNS changes, validation paths are blocked, the domain is removed from hosting, or account limits are reached. Configure monitoring that alerts an address watched by more than one responsible person. Do not rely on a calendar reminder alone.

If expiration is close, start renewal early and verify installation after issuance. A renewed certificate stored in the panel has no effect if the web server still presents the old one. Confirm the public serial number or new validity period, then test all important hostnames and proxy layers.