Vérificateur de certificat SSL

What we check

• Trust – whether the certificate chains to a root that browsers trust.
• Nom d'hôte – whether the name you entered is listed in the certificate.
• Expiry – days remaining. Let’s Encrypt certificates last 90 days or less and should renew automatically about 30 days before expiry.
• Chain – each certificate the server sends. A missing intermediate works in some browsers and fails in others.
• Protocole – the TLS version and cipher negotiated.

Common fixes

“Unable to verify the first certificate” – serve the full chain (fullchain.pem), not just the leaf certificate. Host name mismatch – issue a certificate that includes this exact name, or a wildcard. Expired – check your ACME client’s renewal logs and any Enregistrements CAA.