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SSL Certificate Checker

Check a site's SSL/TLS certificate: issuer, validity dates, days left, TLS version and SAN domains.

We connect on port 443 and read the certificate.

Next step: Security Headers Checker

About the SSL Certificate Checker

Checks a site's SSL/TLS certificate — who issued it, when it expires, the TLS version and which domains it covers. An expired or misconfigured certificate breaks HTTPS and scares off visitors.

What this tool checks

Frequently asked questions

HTTPS is a ranking factor?

Yes — Google uses HTTPS as a lightweight ranking signal, and browsers warn on sites without it.

My certificate expires soon — what happens?

Once it lapses, browsers show a full-page security warning and blocked HTTPS. Renew (or enable auto-renew via Let's Encrypt) before then.

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