Enter a domain name to instantly see SSL certificate expiry, issuer, Subject Alternative Names, and validity — free, no signup required.
Type any domain name (e.g. example.com) — no need to include https:// or www. Just the base domain.
The checker connects to the domain's SSL endpoint and retrieves the full certificate details — expiry, issuer, SANs, and chain.
See exactly how many days remain, who issued the certificate, which domains it covers, and whether the certificate is trusted.
The checker shows: certificate expiry date and days remaining, issuer (Certificate Authority), subject (domain name), Subject Alternative Names (SANs — all domains covered by the cert), validity period (issued date), serial number, and chain validity status.
Expired SSL certificates break HTTPS connections and show security warnings to visitors, which destroys trust and hurts SEO. Most certificate authorities now issue 90-day certificates (including Let's Encrypt), making regular expiry checks even more important. Checking before expiry allows you to renew in time.
SANs (Subject Alternative Names) are additional domain names that the SSL certificate is valid for. A wildcard certificate like *.example.com covers all subdomains. A multi-domain (SAN) certificate can cover completely different domains. The checker lists all SANs so you can verify your domain is included.
Best practice is to renew at least 30 days before expiry. For Let's Encrypt certificates (90-day validity), certbot typically auto-renews at 30 days remaining. Commercial certificates should be renewed at 60–30 days out to account for validation time. Set a calendar reminder or use automated monitoring.
