SSL Certificate Checker
An expired or mismatched certificate throws a browser warning that scares visitors off in seconds. This checker connects to a domain, reads the TLS certificate it presents, and reports who issued it, the window it's valid for, and how many days remain — so you find the problem long before your users do.
What you get
- The issuing certificate authority and the chain it was signed under.
- Valid-from and valid-to dates, with the days remaining until expiry called out.
- Whether the certificate actually matches the hostname it is serving.
- An early warning on certificates that are close to lapsing.
Frequently asked questions
- What does this checker actually test?
- It performs a live TLS handshake with the domain, then inspects the certificate the server returns — issuer, validity dates, and the hostnames it covers.
- My certificate auto-renews. Do I still need to check it?
- Auto-renewal fails more often than people expect — a misconfigured ACME client or a DNS change can quietly break it. A periodic check is cheap insurance against an outage.
- Does this work for any domain?
- Any domain serving HTTPS on the standard port. If a site has no certificate or doesn't answer on 443, the result will tell you that directly.
- Does a check cost credits?
- Viewing this page is free. Running an SSL check uses 1 credit; repeat checks of the same domain are served from cache at no charge.