Free SSL Certificate Checker
Check SSL certificate validity, expiration date, certificate chain, and security details for any domain. Instant results, no signup.
An SSL certificate ensures encrypted communication between a browser and a web server. Expired or misconfigured certificates trigger browser warnings, break user trust, and hurt search rankings. Use this free checker to verify any domain's certificate validity, expiry date, and chain of trust in seconds.
How It Works
Enter Domain
Type any domain name (e.g., example.com). No need to include https:// or www.
TLS Connection
We establish a secure TLS connection to port 443 and retrieve the full certificate chain.
Detailed Report
View issuer, expiry, SANs, chain validity, fingerprint, and protocol version instantly.
What This Tool Checks
Frequently Asked Questions
This tool connects to port 443 of your domain over TLS and retrieves the full SSL certificate details including issuer, subject, validity dates, days until expiry, Subject Alternative Names (SANs), certificate chain, SHA-256 fingerprint, and the TLS protocol version used.
Yes, completely free with no signup required. You can check up to 20 domains per 15-minute window. For continuous automated SSL monitoring with expiry alerts, sign up for GoPinger.
A valid certificate chain means every certificate in the chain from your server certificate up to the root CA is properly signed and trusted. A broken chain can cause browser warnings even if the leaf certificate itself is valid.
Best practice is to renew at least 30 days before expiration. Let's Encrypt certificates are valid for 90 days and their tools auto-renew at 30 days. For paid certificates, start the renewal process at least 2 weeks early.
Common reasons include: expired certificate, hostname mismatch (the domain you checked is not listed in the certificate's SANs), incomplete certificate chain, or a self-signed certificate not trusted by public CAs.
This tool gives you a one-time snapshot. GoPinger SSL monitoring checks your certificates automatically on every uptime check and sends alerts at 30, 14, and 7 days before expiry so you never miss a renewal.
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