The Biggest Mistakes in Google Tag Manager And How to Avoid Them

Google Tag Manager (GTM) is a free tool provided by Google. It is commonly used to implement new analytical services. I encountered a lot of mistakes made while implementing GTM and helped to correct any errors for my clients. To my experience, it is not that difficult to implement it flawlessly but you need to be careful and precise while doing it. Let’s see what are the biggest mistakes in implementing Google Tag Manager and how you can avoid all of them!

In this article I will describe:

  • What is GTM
  • How can you benefit from using GTM
  • Is a GTM the right choice for you
  • What are the biggest mistakes while implementing Google Tag Manager
  • How to avoid the most common errors.

Google Tag Manager – What Is It?

Google Tag Manager is commonly used for web analytics purposes. It is a free and useful tag management system. You can access it by signing up to Google Tag Manager. It gives the possibility to speed up the whole tag implementation and management process. Thanks to GTM, you can create as well as monitor tags on a user interface without repeating the same work over and over again each time you need to add a new tag. This is also the way to bypass IT (to cope with implementation when you cannot count on IT support). You just embed the GTM’s code into each page of your website. Then, when you want to create a tag, Google Tag Manager codes it and embeds it on your website automatically. This way, it eliminates the manual process of constructing tags and makes your marketing process much more efficient.

How GTM Makes Your Life Easier?

GTM has many benefits and I know that every analyst or marketer with experience loves it.

Faster Implementation

It is really easy to implement new tags when you use GTM, therefore it is just fast. Google Tag Manager just prevents you from adding code on every page of your website. Moreover, it is a dull task that needs to be done precisely so better delegate it to the system that makes it automatically. Thanks to that, you and your team can focus on a bigger picture and the possibility of human error decreases!

In addition, GTM is an enormous time-saver for digital marketers. Before, if they wanted to set up conversion tracking they would have to create a task for the IT department and wait for the implementation for a long time. With GTM, there are no more costly delays. Thanks to it, work goes smoothly and independently from others. 

Easy Control And Maintenance

Thanks to GTM you can easily control and maintain all the tags you need. It doesn’t need much work to organize them, delete or add the new ones.

Clear Responsibility

In the GTM, you grant access per mail, that is how you can see who changed what, who added a new tag, who implemented something with an error. You can see who has done a good job, and who has made mistakes. Most importantly, that is a great adjustment because you know to whom you can turn in regards to the particular tag’s implementation.

Easy Roll-back And Changes in Tags

Thanks to the history versions you can easily change the implemented version of your tags. It is especially useful when you misimplement the new tag and want to roll-back to the previous version of your GTM container.

Painless Tag Debugging

Within Google Tag Manager, you can easily debug all the tags and make sure your configuration works as expected. GTM’s preview mode lets you browse a website on which your container code is implemented. As a result, you can test a container configuration before it is published and inspect which tags fired and in which order.

Defined And Ready to Use Tag Templates And Variables

GTM has a wide range of built-in variables to choose from. They provide us information related to the visited page, clicked element, watched video or the threshold of the page that we’ve reached. So they are placeholders for the values that can change with particular interactions. Additionally, for more specific cases we can also configure our own, custom variables – like constants, RegEx tables, JavaScript or Data Layer variables and many many more.

Great Integration With Google Products

As a Google Product, GTM can be easily integrated with many useful tools provided by the company. You can easily connect it with Optimize, Google Analytics or Display Ads. 

Better Page Performance

Website loading time slows with many tags, that are followed by many more bits of code. Tag Manager simplifies it and allows to create a variety of custom tags. In addition, Google states that GTM could speed up the load time of your website if you implement it correctly. But not in all of the cases. It depends on the tags. GTM is not always recommended in the matters of the better page’s speed. There are cases in which it is better to implement tag directly without GTM. And this is also about tags from Google, like Google Optimize tool designed to perform A/B tests. They just recommend adding Optimize’s tags directly to the website to perform tests more accurately.

Is GTM the Right Solution for Me?

Well, if you need to add new tags now and then, it is a good solution for you. But let’s remember that we have also other tag managers like Adobe DTM or Tealium.

Moreover, if you run a small website and have already implemented one analytical service that suits you, you can skip that more advanced level of organization that stands behind GTM. However, it may get confusing. If you already implemented Google Analytics for your blog and after some time you decide on starting Facebook Ads Campaigns you will need the implementation of the Facebook pixel, and GTM makes it just easier. If you implement GTM, you are allowing yourself space and easy way to grow, change directions and analytical providers – it just simplifies your life a lot. 

What Are The Biggest Mistakes in Google Tag Manager?

I have encountered many mistakes that people made during implementation or misusing Google Tag Manager. Let me share with you the ones I consider the biggest.

Over-Tracking Events 

Tracking every click, interaction or scroll can slow down your website’s loading time. But also, it can prevent you from identifying the most important data. You can not take a look at everything and easily see patterns that may be essential for your business to recognize. Remember – quality over quantity. Identify the key interactions, events on your website, and add tracking there. Above all, it will make reporting easier and you will not get distracted by too much less relevant information.

Overly-Specific Tags in the GTM

Another common mistake is that users often create triggers that are overly-specific. For example, if you have many different phone numbers provided on various pages of the website, and you would like to track any time users click a phone number, one tag should be enough. Use custom or built-in variables to gather more information at once instead of having a lot of tags for similar purposes.

Forget to Annotate Your Version Changes

A version is a snapshot of your container in the Google Tag Manager at any given time. Google allows you to annotate the new version of your container every time you publish new changes. Thanks to it, you can provide additional details on what you have changed or added. It is useful, especially when you find an error in your tracking and want to revert to an older version. You can do it by using the version’s name and details. Certainly, it is a great way to save yourself trouble in the future! 

Check All the Typos

When the tag doesn’t fire, always check for typos in trigger’s conditions and names of the variables. Most often typos happen in the Data Layer variable. All in all, they are common and most human of the mistakes.

Defining DataLayer After the GTM Container Script

Sometimes we don’t realize how important it is to put scripts in the right place of the source code. Before we are surprised that our GTM is not working properly, let’s check first if the DataLayer definition is not after GTM snippet. Such a location can cause GTM to be broken completely or make the PageView event not working.

Wrong Naming Convention

It is often found on websites that tagging page elements were done by different people, each with their own naming convention (or by one person who does not pay attention to the events’ structure). Then we have the situation of this type:

Event CategoryEvent ActionEvent Label
Element Click/about-us.htmlLearn more
Element clickSliderOur clients

In such cases, there is no consistent convention between the category, action, and label of the event. Then the analysis of users’ behaviors on our website is difficult or even impossible to conduct.

Therefore, before you start to tag your website, you should prepare a plan – write down the structure of each event that you would like to track. Such a document will allow you to have a bigger picture of the situation. Thanks to it, you will understand that the clear event structure makes analysis faster and easier and is understandable for everyone who uses it.

Conversions Tracked Not Properly

Everyone knows that you must track conversions on your website. Depending on the service it can be e.g. form submission, newsletter subscription, purchase or share of the article on the blog page. However, we do not always know that conversions are often measured improperly!

The most common case is connected with form submissions. Conversion is often measured on the “Submit” button click. That’s a big mistake! Such click in most cases does not lead to conversion. You can do it by accident or click when not all required fields are filled (or filled fallibly). We should fire the event only after correctly submitted form – so e.g. on thank-you page or when a particular pop-up appears. However, we can also gather the “Submit” button clicks – the knowledge regarding the percent of users correctly submitted the form to those who clicked the “Submit” button may be also valuable information.

Workspace with Bugs

When we use a lot of JavaScript scripts, there is some probability that our code has a syntax error. Depending on the situation, the result may be a non-working variable, but sometimes the problems can be more serious. Therefore you must be careful! While publishing, make sure you do not encounter (and you don’t miss) warnings like this one below.

Google Tag Manager with No Secrets

As you can see above, we all do mistakes and it is not uncommon. But with every error, we can learn some more. Therefore, it takes some time and experience to master Google Tag Manager. Hopefully, you will avoid some of them thanks to my article because it is “cheaper” to learn from mistakes made by others. 😉 If you know other common mistakes or omissions in Google Tag Manager, do not hesitate to share them with me in the comments!