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SSL Checker

Available

Inspect a website’s TLS certificate: validity dates, issuer, subject names and certificate chain.

SSL Checker

Domain name serving HTTPS

TLS port

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How it works

The server opens a TLS connection to the host, reads the presented certificate chain and checks validity dates, hostname match and chain completeness.

Safeguards & responsible use

  • Server-side input validation: only syntactically valid hostnames and IP addresses are accepted.
  • Private, loopback, link-local and reserved address ranges are blocked to protect internal infrastructure.
  • Per-client rate limiting and request timeouts.

Frequently asked questions

What does “incomplete chain” mean?

The server is not sending the intermediate certificates browsers need to link your certificate to a trusted root. Some clients will then fail to connect.

How early should I renew?

Automated certificates (such as Let’s Encrypt) usually renew 30 days before expiry. Set alerts well ahead of the expiry date.