Using Firefox DevTools to Troubleshoot Your Matomo Tag Manager

Is this thing working? Is this thing on?

1. How to use devtools to confirm some MTM containers are attached to your site.

Check to see that deployment is working for your container (or containers).

 In screenshot above notice that I have three containers in my dashboard. Let's check the live site for containers:

1 and 2 show the HTML of the page requesting to load the container. We conclude there are only two chunks of script in our HTML calling for a MTM container to load. 

Let's look in the HTML. If we search the source code for the website we will indeed see two containers have been requested by the page (not three).

A note about having multiple containers in Matomo Tag Manager
The easiest case is to have one container on your site.

But MTM is only okay at organizing your tags. So you may have been motivated to create two or more tag manager containers, treating them as folders.  CAVEAT: Be organized.  Down the road, someone (maybe you!) will not know how these were set up and will go around in circles, not realizing there are multiple containers of your tags.

As we saw, above, only two of the three containers from the Matomo dashboard were even active in our site.