Use this free SSL certificate checker to instantly verify any domain's SSL/TLS certificate. See expiry date, days remaining, issuer, cipher suite, and all Subject Alternative Names (SANs) — no login or installation required.

What does this tool check?

Certificate validity period (issued on / expires on)
Days remaining until expiry with a visual progress bar
Certificate subject (Common Name, Organization)
Issuer details (CA name)
TLS protocol version and cipher suite
SHA-256 fingerprint
Subject Alternative Names (SANs) — all covered domains

Why monitor SSL certificates?

An expired SSL certificate causes browser warnings and breaks HTTPS for all visitors. Google also uses HTTPS as a ranking signal. Checking your SSL regularly ensures your site stays trusted, secure, and optimized for search engines.

How to use

Enter any domain name (e.g. github.com) or paste a full URL. The tool connects directly to port 443 and reads the live certificate — showing real-time results in under a second.

Frequently Asked Questions

Does this tool support wildcard certificates?

Yes — wildcard and multi-domain certificates are fully supported. All SANs are listed in the collapsible section.

Is my domain sent anywhere?

The check is made server-side via a direct TLS connection. No data is stored or logged — results are returned only to your browser.

What does "Critical" status mean?

If fewer than 7 days remain before expiry, the certificate is flagged as Critical. Renew immediately to avoid service disruption.

Can I check an internal or localhost domain?

No — the checker connects from our server. It works only for publicly reachable domains that accept TLS connections on port 443.