Check certificate expiration
Enter a public hostname to see validity dates and how many days remain before expiration.
Security tools
SSL Certificate Checker
Inspect SSL certificate issuer, subject, validity dates, SAN entries, fingerprint, and expiration.
Checks port 443 on public hostnames. Local, private, and reserved network targets are blocked.
Certificate report
Run a check to inspect issuer, dates, SANs, and validation.
Certificate details will appear here after the first check.
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About SSL certificate checks
SSL certificates identify HTTPS sites and define the hostnames and date range a certificate is valid for. Checking certificate details helps debug HTTPS setup and expiration issues.
Common uses
- Check certificate expiration
- Inspect issuer details
- Review subject alternative names
- Debug HTTPS validation errors
Notes
This checker connects to port 443 on public hostnames only. It does not check private network hosts or custom TLS ports.
Examples
Inspect issuer and SAN entries
Review certificate issuer, common name, and subject alternative names when debugging HTTPS setup.
FAQ
Does this checker store hostnames?ShowHide
No. The checker opens a live TLS connection for the requested public hostname and returns certificate details without storing files.
Can it check internal hosts?ShowHide
No. Localhost, private IP ranges, and non-public hostnames are blocked.
What does authorized mean?ShowHide
Authorized means the certificate chain validates according to the server environment. Some self-signed or incomplete chains may show an error.
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