Google Tag Manager vs Google Analytics – Which tool to use?

Google Tag Manager or Google Analytics? You’re not the only earthling wondering which tool you need to achieve what exactly. In this article, you find all the answers to everything you always wanted to know about GTM vs GA, but were afraid to ask.

Key takeaways

  • Google Tag Manager (GTM) and Google Analytics (GA) are complimentary tools.
  • GA collects data. GTM, on the other hand, is useful to implement and configure GA and customize event tracking of GA.
  • You can use GA without GTM, but you may not be able to collect all the data you need.
  • You can also use GTM without GA. It is a powerful Tag Management System.
  • Learning the combo “GA and GTM” can boost your business or career. 

Google Analytics at a glance

Google Analytics is the most popular free web analytics platform. It provides businesses and organizations with data about how people enter and behave on a website or app. 

This data is presented in reports, graphs and tables like this one: 

There is a lot more to say about GA, but for now, you hopefully have a good idea about its main purpose. 

Let’s take a step back. To activate GA on your website, you need to put the GA tag inside your site’s code

This is where GTM enters the stage (but not leaves). So, let's have a closer look at what this tool is capable of. 

What is Google Tag Manager?

GTM is a free Google tool that allows you to manage tracking tags and code snippets on a website or app without having to make changes to the code. 

In its simplest form, this looks as follows:

Simply said: GTM injects tags of other tools directly into your site code

#1 Install tracking tags, such as GA4

The first thing you can do with GTM is implement, for instance, the Google Analytics tag on your site. 

GTM can also add tags from 3rd parties, but I will get back to this later on.

#2 Configure GA4 events

Besides implementing a GA tag (Universal and GA4), GTM can also help you configure GA4 events without changing your website code. 

You can configure your GA4 property in such a way that it collects a lot of data automatically. 

But not all websites are the same. If you want to have specific data in GA4, you have two options. 

  1. Add small code snippets to the code of your website.
  2. Use the no-code interface of GTM, which will then add these to your site.

To make this less abstract, I give you a couple of data collection use cases that require both GTM and GA. 

  • Measure the exact scroll depth. GA4 automatically triggers an event if somebody has scrolled to 90% of a web page. If you want to measure other percentages, or use measure unit, you need to use GTM.
  • Custom dimensions. You have to create tags in GTM. In GA4, you can then configure the dimensions.
  • User properties. Here too, you need to create them in GTM before they show up in GA4. 
  • Recommended events. These are events you can add on top of the default ones.
  • Tracking clicks. If you want to track specific links, you will need to use GTM. 

All of this hopefully makes it clear that Google Tag Manager is not a part of Google Analytics.

If GA is a naked Christmas tree, GTM are the lights and decorations

The tree remains the same. But you can remove and add details to make it fit better in your room.

This brings us to an interesting question…

Do I need Google Tag Manager if I have Google Analytics?

No, you can use GA without GTM. This is often the easiest way to implement the GA tag on your site. 

However, from a data-driven analytics point of view, this is the most limited option. 

The table below summarizes when you can safely use GA without GTM.

Depending on your website software, you can add the GA tracking tag without GTM in 3 ways: 

  1. Manually add it to the source code.
  2. Implement it with the help of a plugin.
  3. Some website software provides a field where you can enter the GA4 measurement ID of your property

Easy, and yet implementing the tracking code of GA in the wrong place is the number one reason GA is not working

Pardon me for the unsolicited advice, but if you care a tiny bit about web analytics data, implement GA with GTM. Or have your agency or web designer do it for you.

Do I need Google Analytics if I have Google Tag Manager?

GTM is a free Tag Management System (TMS). This means that even if you, or your customers, don’t use Google Analytics, it can still be a valuable tool for your business. 

As a side note: the same is also true for Google Analytics and Google Search Console

Let’s have a quick look at what makes GTM a popular TMS for marketers and developers.


GTM uses a container. You can fill that up with whatever tags, scripts, code snippets you need.

Besides GA tags, you can choose from a library of template tags from 3rd parties.

  • The usual suspects: LinkedIn, Pinterest, Google Ads, Reddit, Quora…
  • A wide variety of tags from the Community Template Gallery. 

And if you want to, you can even use custom tags.


You can add, edit and delete tracking tags directly in GTM instead of implementing them on your site with a bunch of plugins, or changes to the source code. 

The risk of breaking your data collection machine is obviously smaller thanks to GTM.


“System” may sound somewhat different from what I called at the beginning of this article a “tool”. 

But then again, I hope you understand at this point that GTM can be much more than a handy tool for your business.

If not, allow me to add 4 more convenient features of GTM that prevent misunderstandings and delays between your marketing and development department.

  • Version history: you can control and manage containers. Is something broken? You can roll back to a previous version of the container of tags.
  • Users: like in GA, you can give team members access to your GTM account. 
  • Workspaces: You can create multiple workspaces for departments or teams. This will keep your tags even better organized.
  • Target platforms: In GA, you can use a web stream, iOS and Android. GTM offers you two more target platforms: AMP and Server side tracking

So, GTM and GA are nothing but roses and moonshine? 

Actually, yes. 

Before you jump into GTM, you may have some minor questions. Below, you can find the answers to the most common ones. 

FAQ before you actually start with GTM

Can you have Google Tag Manager and Google Analytics on the same page?

You can load the GTM and GA script on the same webpages. Yet, this will result in duplicate data in your reports. 

This situation typically occurs when you switch from a standard GA implementation to an integration with GTM. 

Therefore, checking if a site has GA is the first step you need to take if you plan to switch to GTM. 

Will I lose historical data in GA when I switch to GTM?

No, you will not lose historical data in GA when you start using GTM. The platforms are separated and GTM does not collect data. It only implements tags on your site. 

There is, however, a risk that you will not collect all the relevant data after the switch. 

If somebody added tags manually to the source code, this may cause duplicate data, or no data, for specific events. 

The best you can do before switching to GTM is:

  • Talk with your web or app developers. 
  • Document all the data, metrics, KPIs, conversions… you are currently tracking in GA.
  • Make a list of all the hard-coded tags (GA and other platforms).
  • Implement them one by one in GTM. 
  • Test if they work.
  • Remove the manually added tags from your website code.

Does GTM slow down your site?

Adding scripts from 3rd parties to your site can slow down your site. The advantage of using GTM is that it gives you more control on when to fire the tags.

You can, for instance:

  • Load scripts and tags on specific pages only. 
  • Configure the trigger to fire a tag only when a condition is met that doesn’t mess with your site speed metrics

Do I need different emails to access GTM and GA?

You can create a GA and GTM account with different email addresses, but it is not an absolute requirement. 

If you are an agency or an IT administrator in an enterprise, this is a smart choice from a security point of view.

In both GA and GTM, you can add users with different roles and permissions. 

This way, the development and marketing team can work separately on the common bigger goal: growing your business or organization. 

Final note: head start with GTM and GA

GA and GTM are a match in heaven. One tool collects the data, the other one keeps tracking tags organized. 

There is only one link missing. 

The tools need brains and a hand to work together. 

You can be that missing link. 

As a marketer, developer or data analyst, it is worth mastering Google Analytics and Google Tag Manager to bring more value to your employer, career or customers. 

To get you started in no time, the Data Driven U team composed a practical set of free GTM resources. Grab them now. 

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