How To Check If Google Tag Manager Is Installed On A Site?

how to check if google tag manager is installed on a website
Ravi Davda Rockstar Marketing CEO

Written by Ravi

Nov 30, 2020

Share this:

In this article, we’re going to take a look at how to check if Google Tag Manager (GTM) is installed on a website. It can be your own or any other site that you want to check, like one of your competitors.

Google Tag Manager, or GTM, is a prevalent script management system for the easy installation of scripts, tags, and other code to your website without interfering with the source code of your site. Except for adding the GTM code, of course.

We’re not going to look through the reasons for having GTM. That is because we would like to think that if you’re searching for how to check if GTM is installed, then you already understand the reasons for installing it in the first place.

How do you check if GTM is installed?

There are various steps that you need to complete to check if you have Google Tag Manager installed on your site correctly.

  • Check The Source Code
  • Tag Assistant (By Google)
  • Use Debugging mode
  • SEO Audit Tools
  • Dev tools

We’ll look through each of the steps in a little more detail below.

Check the webpage source code

The easiest way to check if your site, or any other site, has GTM installed is through the source code in the browser. This method is probably the easiest out of them all!

  • Go to the webpage you want to check. – Are you there? We can wait
  • Right-click on the background. – Not an image. If your right-click menu shows “copy link address” or “copy image address” it is not the background. You should see “view page source.” However, the shortcut is Ctrl+U
how to check if google tag manager is installed on a website guide
  • Click on “view page source.” – A new tab will open
  • Press Ctrl+F. – That will open a search dialogue box. – Your cursor will automatically go into the typing box
  • Type in: gtm.js. – Caps Lock does not make a difference here

If Google Tag Manager is installed properly, you will see at least one occurrence with the “gtm.js” text surrounded by <script>.

how to check if google tag manager is installed on a site today

You may have an instance where “gtm.js” is surrounded by <noscript>. That is not a necessity for correct installation, though. <noscript> is what visitors whose browsers cannot load script will see, for example, people with ad blockers.

Tag Assistant (By Google)

Another easy way to check your GTM installation is through the Tag Assistant (by Google) Chrome extension. The GTM extension will allow you to check for various Google properties such as GTM, AdWords, Analytics, etc.

After you install the extension, it is another simple process to check GTM status. You will want to click “done” on the first popup :

install gtm

Next, click “Enable” to allow Google Tag Assistant access.

google tag assistant access

Click “Refresh” on your browser, or press F5.

After your page has refreshed, you can click on the extension link again. You will then see another popup showing the tags for the page you are on.

google tag assistant tags

You are looking for the green smiley tag with Google Tag Manager next to it. That’s it, you know have another confirmation that your GTM is installed correctly.

How to check if Google Tag Manager is installed on a website – Use GTM debugging

Another easy way to check GTM and that it is working correctly is to use the Debugging option on your Tag Manager console.

Once you have logged in, you need to choose the domain that you wish to check.

google tag manager debugging

At the top right of the screen, click on the “Preview” button.

Smart Tag Assistant will appear, and you can enter the URL of the site you want to check.

smart tag assistant

Click “Start.”

Now, another window will open with an info bubble explaining that the Debugger is connected. Do not close this window, but you can minimise it.

google tag manager debugger connetcted

Back to the original Tag Assistant page, you should have a Connected popup. Press “Continue.”

google tag manager

Open up the Debugger window, and if you can, use it on a different screen. That makes it easier to see both the Tag Assistant page and the Debugger.

However, if you do not have two screens, you can split the screen so that you can see both windows at the same time:

google tag assistant and debugger

You can now interact with your website (on the right, here), and see which tags fire when you open different pages on the Tag Assistant page.

Providing you receive notifications to show that tags are firing when you open all of your pages, you know that you have no issues.

Tag Manager and SEO audit tools

While you were running through the GTM Debugger, you may have noticed some of the pages not firing tags. However, if you have a large website, you are unlikely to have the time, patience, or inclination to go through every page and post. That is where SEO Audit tools such as Screaming Frog and SiteAnalyzer help.

Using SEO tools like these may look complicated to people who have never seen them. However, if you’re only looking for GTM information, you can use them pretty easily.

Screaming Frog

Screaming Frog will require the paid version for this, but if you are having big problems, it can pay for itself pretty easily.

Go to:

  • Configuration
  • Custom
  • Search

Enter the condition: Does not contain

Insert the root URL of the site you wish to scan and click “Start.”

screaming frog

You will now see a list of all URL’s that do not include your GTM code.

Check Site Analyzer

Site Analyzer is very similar to Screaming Frog, but it is a free software. The process is slightly different, but just as easy.

Click on:

  • Sites
  • Content Search (or press Ctrl+F)
  • Change the dropdown to “Not Includes.”
  • Enter the same text as above:
site analyzer
  • Press OK
  • Click “Start”
site analyzer url list

You will now get a list of all the URLs in your domain that do not have the GTM code.

How to check if Google Tag Manager is installed on a website – Use Dev tools

Developer tools are a way to look a little more in detail at your codes. However, finding the issues is not much more difficult than making a cup of tea.

When you are on the site that you want to inspect, in Chrome browser, you can enable the developer tools in one of two ways:

  • Ctrl+Shift+i
  • F12

If you are on Windows, you will see a console on the right of the screen:

dev tools

Click on “Console”.

Scroll through the code looking for errors. They’re usually highlighted yellow or red.

While you are scrolling, look for words such as gtm, Tag Manager, etc. If you see any of them, you will probably want to contact a developer to have a look at the issues. If you do not know a developer, feel free to use the button at the bottom of the page, and we can help you out.

Next, click on “Network”.

You will need to refresh your browser for the data to appear. However, when the browser refreshes, search for gtm and look for gtm.js?id=GTM xxxxxx (the xxxxxx will be your own gtm code.)

If the status is 200, everything is OK.


If you had read through this article before you tried any of the steps, it may seem like checking if GTM is installed correctly on a website is a little difficult. However, if you followed the steps as you read them, you will have found that it is easier than you think.

Again, if you did go through the article before trying, going back to the beginning and trying it as you read may be an easier way to check the GTM status. However, if you do have any issues with the Google Tag Manager, please feel free to contact us, and we will be happy to help you.


Share this:


  1. download

    Really informative article. Much thanks again. Much obliged.

    • Ravi

      Yes, Google Tag Manager can get confusing, which is why we decided to put this article together in the first place!

  2. tek part

    Some genuinely great content on this site, regards for contribution. Shane.

    • Ravi

      Shane – thank you for reading it. It’s only because of people like you that we’re able to continue this.

  3. 720p

    I must thank you for the efforts you have put in writing this website. Lesly Oates Mitchell

    • Ravi

      We’re glad you enjoyed it! Thank you for stopping by.


Submit a Comment

Your email address will not be published. Required fields are marked *