Introduction to Google Tag Manager (GTM)

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As Google Analytics was live for already 7 years, Google launched in 2012 a new tool, Google Tag Manager, to make the tag management on websites more simple. Many people think that Google Tag Manager is quite similar to Google Analytics, but it is not. We will see there what exactly is Google Tag Manager, what it should be used for, and why we should definitely use it.

What is Google Tag Manager (and what is it not)?

As a webmaster, you may have to implement some tags onto your website, such as your web analytics tool tag (eg. Google Analytics tag), but also some conversion tag for each of your traffic source. Until now, you were adding directly your JavaScript tags directly onto your source code, or you were not tagging anything at all.

A Tag Manager is a tool that will manage all your tags. And that’s all. It will not save your data such as Google Analytics or allow you to make beautiful reports. The Tag Manager has a very precise role. Google Tag Manager is one of them.

The 3 main elements of Google Tag Manager

Google Tag Manager uses 3 main elements in order to manage properly tags:

  • Tag: a tag is a snippet of code, usually in JavaScript, that will be added to the page. This is generally the code that is given by your third-party provider (Google Analytics, any marketing platform…)
  • Trigger: a trigger define when and where a tag will be executed (or fired)
  • Variable: a variable stores data and can be used in both tags and triggers. A variable can be for example the page path, but also, your Google Analytics account ID.

You can have many of each of them; you can use a trigger to trigger several tags, use a variables in one or many tags and trigger.

Google Tag Manager dashboard

Google Tag Manager dashboard

Built-in tags and triggers

GTM includes built-in tags, that make configuration really easier. In case you need to use one of these built-in tags, you would just need your account ID for the third party provider to do a basic configuration of your tag.

Example of built-in tags (partial list)

Example of built-in tags (partial list)

It also includes some built-in triggers, such as the pageview, but also some click triggers to help you tracking clicks on some specific parts of your website.

Examples of built-in triggers

Examples of built-in triggers

Using these built-in features may help you to start implementing GTM.

When should you use Google Tag Manager?

You should probably think about using Google Tag Manager as soon as you have a few tags on your website, to avoid to have them hardcoded in your website source code. Doing so would avoid you having to deploy all your website anytime you want to add or manage your tags. Indeed, you just need to add Google Tag Manager snippet of code on your website, and it will automatically add any tags on your pages, according to the triggers.

Why should you use GTM?

Multi-tag provider

We’ve previously mentioned Google Analytics as one of the examples of tags that can be managed by GTM, but GTM can manage any type of tags, not only Google-made tags.
Google Tag Manager can handle:

  • other Google products tags
  • all built-in tags
  • any other tags through custom tags

You don’t have any limitation regarding the tag provider using any of the custom tags.

Custom HTML/JavaScript tag creation

Custom HTML/JavaScript tag creation


While adding a new tags, trigger or variable, GTM will do a basic check to make sure that your element is valid. For sure, it is not a human validation, so if some of the variables are undefined, it will not be able to know it, but it will raise an error for JavaScript errors, for example, avoiding to add some invalid code on your production server.

GTM is free

Google Tag Manager is provided by Google as a free tool.

Debug tool

GTM includes a debug tools that help you understand what data is available when a tag is executed, and which tags are executed and when.

Example of debug tool use

Example of debug tool use

History of all modifications

When you add, edit or remove some tags, triggers or variables, you need to deploy a new version of your account. GTM keeps every version so you can easily roll back to a previous one!


They are many more reason to use Google Tag Manager. Some require a more advanced knowledge about Google Tag Manager, that we will address in future posts.

Google Tag Manager is a great tool that can be implemented and used without advanced skills as it relies on a simple and clear interface. It will give you more confidence in managing your tags, save you time and give you lot of agility for tag management.



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