Free SSL certificate checker — see when a domain’s certificate expires, and who issued it.
Every other tool on this site runs entirely as JavaScript in your browser and never contacts a server at all. This one is a deliberate exception, by necessity: the domain you enter is used by our server to open a direct TLS connection to that domain on your behalf — unavoidable, since a browser cannot itself inspect an arbitrary third-party domain’s certificate details this way — nothing about the request is logged. Nothing about the request is logged, stored, written to a cookie, or shared with any third party — it's handled and discarded the moment the response is sent back to you.
This describes only what this specific tool does with what you type into it. It doesn't cover the rest of this site — see the Privacy Policy for how analytics and advertising cookies are handled elsewhere.
Enter a domain and see exactly when its SSL/TLS certificate expires, who issued it, and how many days are left — useful for catching an expiring certificate before it lapses and breaks the site with a browser security warning.
This performs a real TLS handshake to the domain on port 443, the same connection your browser makes to load the site securely, and reads the certificate it presents — not a cached or third-party record of it, so the result reflects exactly what a visitor's browser would see right now.
Nothing here touches your own server or account — this only reads the public certificate any visitor to that domain would already receive, the same information anyone's browser shows if you click the padlock icon.
No — it only reads the public certificate a normal visitor’s browser would already receive when connecting to the domain, the same information available by clicking the padlock icon in any browser.
It’s still reported, with a negative days-remaining figure and a clear expired flag, rather than an error — useful for confirming exactly how long a certificate has actually been expired.
Usually because the domain doesn’t serve HTTPS on port 443 at all, or because of a DNS or network issue reaching it — the error message states which of these actually happened rather than a generic failure.
Yes — enter the exact subdomain (like shop.example.com) if that’s what you need to check; a certificate for the main domain doesn’t always cover every subdomain.