SSL Certificate Check
Inspect SSL/TLS certificate validity, issuer, and security configuration
Usage
• Domain: enter a bare domain without https:// (e.g. example.com)
• Checks HTTPS certificate validity and expiry
• Shows certificate issuer and validity period
• Custom port: append :port for non-443 endpoints (e.g. example.com:8443)
What SSL certificate checking is for
An SSL certificate check connects to your domain over TLS, retrieves the full certificate chain, and reports the leaf certificate's issuer, validity window, expiry countdown, and a deep-audit security grade covering cipher suite, OCSP revocation status, TLS protocol support, and embedded SCTs. A single check gives you both the basic validity picture and the detailed security posture of your HTTPS endpoint.
Common uses include confirming a newly issued certificate is deployed correctly, monitoring days-to-expiry before an outage, verifying the certificate issuer after a CA migration, and identifying deprecated TLS versions or weak key algorithms in a security review.
Frequently asked questions
What does 'hostname mismatch' mean?
The certificate's Subject Alternative Names do not include the domain you checked. Browsers will show a security warning for such connections. Reissue the certificate with the correct names or check that you're using the right domain.
How far in advance should I renew a certificate?
Follow the issuer’s current validity, renewal window and automation policy rather than assuming a fixed lifetime such as 90 days. Check the actual notAfter value and allow time to recover from renewal failures.
What is OCSP revocation?
OCSP is a protocol for querying a certificate issuer about revocation status. A certificate can be revoked before its expiry date. Revocation information is one part of validation and does not replace checking the hostname, validity period and trust chain.
What is a self-signed certificate warning?
Self-signed certificates are not issued by a trusted CA, so browsers show security warnings. They are fine for internal or development use, but public-facing services should use a CA-issued certificate.
References and result limitations
Online results reflect the queried source or probe state at that time. Record the target, time, nodes or data source, and parameters when citing them. A single result does not establish continuous availability everywhere.
These references explain protocol or format rules; they do not endorse results produced by this site.