The online detection tool provides two query methods.

First, you can provide the tool with a domain and its corresponding selector.
Second, you can also send an email to the designated email address.

DKIM Record

The tool will look up the DKIM record and show it on the result page.

DKIM Signature

The tool will parse the DKIM signature in email headers and show it on the result page.

Issues

The tool will show the analysis of the DKIM record and DKIM signature(method 2). You can see the issues found by the tool.

Suggestions

At last, the tool will give suggestions on the current DKIM deployment situation of your domain.