SSL Certificate Checker
Inspect a domain's SSL/TLS certificate status, issuer details, expiration timing, and negotiated protocol so you can identify configuration problems before they affect secure access.
What this tool checks
Certificate Validity and Trust
Checks whether the certificate presented by the domain is currently valid and whether the connection can establish an expected trust chain. Use the result to distinguish an expired, untrusted, mismatched, or otherwise problematic certificate from a working HTTPS setup.
Expiration and Renewal Timing
Reports when the current certificate expires so you can judge how much renewal lead time remains. Treat the date as an operational signal, then verify how your certificate is renewed and deployed so an automated or manual renewal does not fail silently.
Negotiated TLS Protocol
Identifies the TLS protocol version used for the checked secure connection. Use that result to confirm that the endpoint supports the protocol policy you intend, while remembering that complete compatibility may also depend on server configuration, client support, and other negotiated settings.
Why Certificate Health Matters
A valid HTTPS configuration helps browsers establish a secure connection and avoid certificate warnings. HTTPS is also a documented Google ranking signal, but certificate health should be treated primarily as a security and availability requirement rather than a standalone ranking tactic. Review validity, host matching, expiry, and protocol support together before changing your TLS configuration.
Common issues this tool detects
An expired certificate can trigger browser security warnings and prevent a normal trusted connection. If expiry is approaching, confirm that the renewal process is active and that the replacement certificate will be deployed to the correct endpoint.
An HTTPS page that still requests some resources over HTTP can create mixed content problems. Review affected scripts, styles, images, fonts, or embeds and update them to secure endpoints only after confirming those endpoints are supported.
The certificate needs to cover the hostname being requested, either directly or through an appropriate wildcard or subject alternative name. A mismatch can trigger browser warnings even when the certificate is otherwise valid.
Frequently asked questions
When should I review my SSL certificate?
Use automated monitoring if your infrastructure supports it, and also review the certificate before its renewal window becomes urgent. The existing guidance on this page recommends a manual check 30-60 days before expiry. Treat that interval as operational planning guidance, then align the reminder with your actual certificate issuer, renewal method, and deployment process.
Which TLS protocol versions should I allow?
The existing guidance on this page sets TLS 1.2 as the minimum and TLS 1.3 as preferred, while recommending that TLS 1.0 and 1.1 be disabled. Apply that policy only after confirming compatibility requirements for your users, infrastructure, and any legacy integrations that still depend on older protocols.