An SSL/TLS certificate encrypts the connection between your website and its visitors, protecting sensitive data such as passwords and payment details. It also proves the site is really operated by the domain owner.

Type your domain into the checker above and click “Check SSL”. You will see the issuer, validity dates, days remaining and the domains the certificate covers.

Yes. The tool is completely free and needs no account or sign-up.

It keeps visitor data private, removes the “Not secure” browser warning, builds trust, and HTTPS is a lightweight ranking signal in Google Search.

Browsers show a full-page security warning and many visitors will leave. Expired certificates can also break APIs, payment flows and hurt your SEO and conversions.

Renew or reinstall the certificate through your hosting provider or certificate authority. Many hosts issue and auto-renew free certificates through Let’s Encrypt, so check your control panel first.

It means the certificate does not list the domain you checked. Common causes are a missing www or subdomain on the certificate, or the domain pointing to a server that has someone else’s certificate installed.

Check after any hosting or DNS change and at least once a month, or set up expiry monitoring. Aim to renew when 30 days or fewer remain.

Yes. You can check the SSL certificate of any public website on port 443 by entering its domain name.

The tool connects to the domain on port 443 through a public certificate lookup service, then runs a separate in-browser HTTPS check and a Google Public DNS query for CAA records.