To the average user, they might all be the same, but after a few headaches from these three, I can promise you they’re different!
We often see conflicting, incorrect, and flawed versions of Google Analytics (GA), Global Site Tag (Gtag), and Google Tag Manager (GTM) implemented on sites, but what do they do and which are preferred?
This is the go-to tool for tracking visits and calls to your site. This is a web service that collects data from your visitors as they browse and interact with your site. There have been a few iterations, including Classic, Universal, and GA4 – but for convenience we’ll just call them Google Analytics.
Google Global Site Tag
This is a relatively new way of connecting your site to your Google Analytics. Rather than installing the traditional GA script on your site through the header, Global Site Tag is basically a script that communicates between your GA and all other services like ads, remarketing, etc.
Google Tag Manager
Which one should I have installed?
This is where it gets a bit tricky. You basically want the GA script to fire once per page and then use other scripts for your follow-up later.
It can mean just a GA script, just a GTM script, just Gtag or several. Either way, the result should be that your GA script fires once and your custom scripts fires as needed.
So if you are using GTM or Gtag to run your GA script, you don’t want a hard-coded GA script. We’ve seen this a few times, especially when transitioning from one to the other and the old code isn’t being removed. A telltale sign of this is a sharp increase in your pages / session and a drop in bounce rates in GA.
Should I change?
Switching to GTM or Gtag from the old GA script is a good idea. Personally, GTM is the preferred method, but it has a pretty long learning curve.
GTM is probably better for agencies or where many people use it because it relies on setting up custom triggers in a web interface.