Public signal checker
SSL Certificate Checker
This checker reads the public TLS certificate presented for a hostname and summarizes core validity signals.
The check uses public live signals and does not make a security, malware, fraud or legal verdict.
Run a public signal check
- HTTP
- DNS
- TLS
- RDAP
- Archive
What this checker analyzes
- Whether a certificate is presented on port 443.
- Issuer, validity start and validity end where available.
- Subject and subject alternative name entries exposed by the certificate.
Why it matters
- Certificate problems can block users, crawlers and integrations from reaching a website over HTTPS.
- Expiry and issuer visibility help teams plan maintenance before a public outage.
What the results mean
- Available means a certificate was returned by the public TLS endpoint.
- Unavailable can mean timeout, handshake failure, no certificate or blocked connection.
- Validity dates should be reviewed before expiry.
Limits of this check
- The checker does not validate every browser trust path or every route.
- It does not scan non-standard ports.
- It is not a full TLS configuration audit.
What should also be reviewed manually?
Review notable values in the context of the actual website, its subpages and connected services. A homepage check cannot prove the complete configuration, legal position or security posture.
FAQ
Is this the same as a full SSL audit?
No. It checks basic public certificate data, not cipher suites, protocol hardening or every endpoint.