ADVEYER · Free Tools

SSL Checker

Check whether a site's SSL certificate is valid, when it expires, which names it covers and whether the chain is installed correctly.

Guide

What is an SSL check?

An SSL (TLS) certificate encrypts the connection between a visitor's browser and your site, and proves the site really belongs to that domain. The padlock and https:// in the address bar come from it.

Our checker connects to your site on port 443 like a browser and reads the certificate and intermediates the server sends. It shows the validity period, whether the certificate matches the hostname and whether it chains up to a root browsers trust, all on one screen.

Use it after installing a new certificate or around renewal time to make sure everything is in place. A missing intermediate is a common mistake that triggers warnings on some browsers and mobile devices.

How to Read the Results

Hostname matches: Is the name you checked among the names the certificate covers? If not, visitors get a security warning.
Trusted by browsers: Is the certificate within its validity period and does the chain complete up to a trusted root?
Days left: Time until the certificate expires. We recommend renewing before it drops below 30 days.
Covered names: Every name the certificate is valid for (SAN). A wildcard such as *.example.com covers all subdomains.
Certificate chain: The server certificate and the intermediates that signed it. A missing intermediate has to be added on the server.

Frequently Asked Questions

How do I find my SSL certificate's expiry date?

Enter your domain and run the check; the expiry date and days left are in the "Validity" card.

What does "hostname doesn't match" mean?

The certificate doesn't cover the name you checked. For example, a certificate issued only for example.com triggers a warning on www.example.com. Use a certificate that covers both.

What does a missing intermediate mean?

The server sends only its own certificate, not the intermediate that signed it. Desktop browsers sometimes cope, but mobile devices and API clients fail. Install the CA bundle from your certificate provider on the server.

What's the difference between free and paid SSL?

Both give the same strength of encryption. Paid OV and EV certificates verify your company's identity and come with a warranty and longer validity, which is why business and e-commerce sites prefer them.

Is only port 443 checked?

Yes. The tool connects only to 443, the standard HTTPS port. For security, servers on local networks and private IP addresses aren't checked.

Protect Your Site with a Trusted SSL

DV, OV, EV and Wildcard certificates at ADVEYER, with our support team on hand for CSR generation and installation.

SSL certificates CSR decoder