Free SSL certificate checker

Enter your domain above and select Check SSL. The checker connects to the site the way a browser does and shows whether the certificate is trusted, whether it covers the hostname, which authority issued it, the TLS version, and the exact expiry date. You can also click the padlock in your browser address bar, but that only shows what your own connection received.

A certificate is valid when four things are true: it is within its validity dates, it was issued by a trusted certificate authority, the server sends the full chain up to that authority, and the certificate lists the hostname you visited. This checker reports each of those separately, so you can see which one fails instead of a single pass or fail.

The result above shows the expiry date and the number of whole days left, coloured green above 30 days, amber from 8 to 30 days and red at 7 days or fewer. To be warned automatically, add the site to Visual Sentinel monitoring: every plan sends certificate expiry alerts 13, 3 and 1 day before expiry by default, and you can add 20 and 6 day warnings.

Public certificates issued from 15 March 2026 can be valid for at most 200 days, under the CA/Browser Forum schedule. The limit drops to 100 days from 15 March 2027 and 47 days from 15 March 2029. Many free certificates, such as those from Let's Encrypt, last 90 days and renew automatically, so an expiry alert is the safety net when renewal silently fails.

SSL stands for Secure Sockets Layer. It was replaced by TLS (Transport Layer Security) years ago, and modern sites use TLS 1.2 or TLS 1.3, but the certificates are still commonly called SSL certificates. This checker shows the TLS version your server negotiated.