This SSL check decodes your SSL certificates and validate intermediate certificate issues.
The list of SSL certificates, from the root certificate to the end-user certificate, represents an SSL certificate chain, or intermediate certificate. These must be installed to a web server with a primary certificate so that your browser can link it to a trusted authority. They are used in Custom SSL zone configurations.
You can use the tool above to decode your SSL certificate and if you are missing an intermediate certificate you will see the following warning.
And if no chain issues are detected you will see the following confirmation.
If you don't install an intermediate SSL certificate web browsers will display an "Invalid certificate" or "certificate not trusted" error. You can use our Certificate Chain Composer Tool to get your intermediate certificates.