SSL certificate check
Issuer, validity dates, covered domains and the full chain — catch expiry and mismatches early.
What we check
Certificate data is shown as returned, with no guesswork; problems are rated by severity.
- Issuer and chain — who signed it, and whether the chain is complete
- Validity — start and end dates, plus days remaining
- Domain coverage — whether the certificate covers the hostname you checked
- Wildcard rules — *.example.com matches one label only, per RFC 6125
- Self-signed check — whether the certificate signs itself
- Cipher suite — the negotiated TLS version and algorithm
- Key type — RSA or ECDSA
How it works
Enter a URL
With or without https:// — we always check port 443
Read the certificate
Every field and the whole chain, listed out
Read the findings
Expired, expiring, mismatched, self-signed, incomplete chain
Other free tools
FAQ
My certificate is installed — why did the connection fail?
Three common causes: nothing listening on port 443, a firewall in the way, or a WAF rejecting connections from cloud servers. We distinguish between them instead of a generic failure.
The certificate is valid but browsers still warn?
Usually the certificate does not cover the hostname you visited, or an intermediate certificate is missing. Both are shown in this report.
Do you store my certificate data?
We only display it. Results are cached in server memory for a few hours to avoid repeat checks.
Why do some sites fail to check?
Some sites deliberately reject connections from cloud servers. That is their security policy, not a fault of yours.
A certificate is the baseline
HTTPS is table stakes, not an advantage. Rankings follow overall content and technical quality.