3 Methods of Verifying if Google Tag Manager Is Installed Correctly

There are tons of articles, tutorials, videos, and step-by-step instructions out there that discuss whether or not your Google Analytics tag is being fired correctly — with Google Tag Manager. However, this post will take a step back, and will demonstrate how to verify if Google Tag Manager is installed correctly in the first place.

Method 1: Simple Copy-Paste Check

This method is actually as easy as it sounds. Here’s how:

  1. Go to your GTM account.
  2. Open your code where you’re able to see both the scripts.
  3. Individually copy the code line by line from GTM, and compare (by pasting), if the exact code is present by going to the source code of the page you expect the GTM code to be on.
  4. Do this for both the <head> and the <body> scripts.

If you’re not able to find an exact match, that doesn’t mean the code is not installed properly. It could just mean that the code base your organization, or your website works with, could add spaces in between, or automatically take things to the next line. When it comes to compiling the code, browsers can understand all of that, but if you’re solely relying on this method, it’s not the most dependable.

Having that stated, if your code gets copied verbatim into your source code as GTM has it, then this is a pretty good way to verify. Although, it’s still not the most accurate way! Keep reading to find out.

Method 2: Using Google Tag Assistant

google tag assistant

To verify with the help of Google Tag Assistant, go to any page you expect the GTM code to be installed. Then, open up your Google Tag Assistant > enable it > refresh the page > and open Google Tag assistant again.

If your code is installed correctly, you should see a green smiley like the screenshot above. You should also see your associated GTM code.

However, before we conclude this method, note the following:

  1. It’s still better to go to the source code, and at least check for the presence of GTM code both in the head and the body. That way, when you see the green smiley in Google Tag Assistant, you can more confidently say it’s installed correctly.
  2. The other important aspect to consider here is that merely creating the GTM code instance and copy-pasting it to your site will not do the trick. You actually have to publish the current workspace for the Google Tag Assistant to be able to pick up on the installation. This is another reason method 1 is not that reliable.

Method 3: Using Chrome’s Network Tab

verifying gtm through chrome network tab

Like method 2, this is another more precise & well founded method. To verify GTM code installation this way, do the following:

  1. Go to any page you expect the code to be installed.
  2. Then, open Chrome’s inspect feature, and head over to the network tab.
  3. Refresh the page.
  4. In the filter, search for “gtm.js.”
  5. If your code is installed correctly, under the name column, you’ll see a value pop-up. Click on it, and another window pane will open. Here, you’re looking for the status code of 200 under the headers tab, as shown in the screenshot above. This means that the script is firing correctly. If by chance you see a 404, it means that you need to publish the current GTM workspace, and check again.

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Verifying if Google Tag Manager is installed correctly is crucial to using what GTM has to offer.

Also, as stated above, method 1 is extremely easy, and doesn’t require any crazy steps. However, it’s not the most reliable. The best way to verify is to use method 1 to simply check for the presence, and then use that along with method 2 or method 3. If you’re someone like me who likes to be more sure than ever, use all 3 methods!

Expert Resources

  1. Analytics mania
  2. Google Analytics Academy