How to create event parameters in Google Analytics 4 (via GTM)?

What are event parameters?

In Google Analytics 4, you can no longer send an Event Category, Event Action, Event Label, and Event Value as you could in Universal Analytics. Instead, you only send an Event Name.

However, to gain more insight into the actions performed, you can also send event parameters. These are additional values that can be sent with an event. You can choose the names of these event parameters yourself, but be careful: you can create a maximum of 50 event parameters.

Thanks to event parameters, you don’t need to create separate events for e.g. each button or form; instead, you can send this data dynamically and keep your configuration organized.

In the first 48 hours, you might see the value “not set” for a custom dimension. The actual values will however appear in GA4 reports later.

You’ll need to be an Editor in order to add/edit custom dimensions.

How to create an event parameter in GA4?

Step 1: Go to the GA4 property where you want to set up the event parameters.

Step 2: Navigate to ‘Admin’ > ‘Data Display’ > ‘Custom definitions’.

Step 3: Click the blue button ‘Create custom dimension’.

Step 4: Fill in the required information and click Save.

• Dimension Name: The name displayed in reports. Use a descriptive name.
• Scope: Event
• Description: Optional text to describe your custom dimension or metric.
• Event Parameter: Enter the name of the parameter or property you want to collect.

How to send event parameters to GA4 via GTM?

Step 1: In Google Tag Manager, go to the event tag to which you want to add event parameters.

Step 2: Click on Event Parameters.

Step 3: Click on “Add Row” and fill in a Parameter Name and Value.

You can pass a Variable as the value, such as the name of a form, the URL of a button, etc.

Step 4: Click Save.

Note: Don’t forget to create a custom dimension in GA4. If you want to send a new parameter, simply making changes in Google Tag Manager is not enough.

Example:

Step 1: Send data to Google Tag Manager with a Data Layer Variable (from the code)

Add this code to your website (via the code or via Google Tag Manager as a Custom HTML tag triggering on Initialization). It is a listener script that waits (listens) for the nfFormSubmitResponse signal (sent by Ninja Forms when a form is successfully submitted). It then pushes the following to the dataLayer (the layer in Google Tag Manager where data is received): an event (ninjaFormSubmission) that we can use as a trigger and two variables (NinjaFormID and NinjaFormTitle) that can be passed as variables.

Make sure the Google Tag Manager code is implemented first; otherwise, the values below will be sent to a non-existent dataLayer.

<script type="text/javascript">
    $(document).on('nfFormSubmitResponse', function(event, response, id) {
        dataLayer.push ({
            'event' : 'ninjaFormSubmission',
            'NinjaFormID' : response.id,
            'NinjaFormTitle' : response.response.data.settings.title
        });
    });
</script>

Which ‘listeners’ and ‘variables’ are available depends on the systems/tools you are using. If you have no experience with this, consult your developer.

Step 2: Create a Trigger in Google Tag Manager

In step 1, we pushed an event to the dataLayer. We will use this to create a trigger, which will eventually allow us to send an event tag to Google Tag Manager. If you already have a trigger set up, proceed to step 3.

1. Go to Google Tag Manager, click on Triggers, and then click New.
2. Click on the Trigger Configuration block and select the trigger type Custom Event under Other.
3. Enter the event name. In this case, it is “ninjaFormSubmission”. Enter a trigger name at the top that is used only within Tag Manager (choose something clear, such as “Custom – ninjaFormSubmission”). Leave “This trigger fires on” set to “All Custom Events”.
4. Click Save.

Step 3: Create a Variable in Google Tag Manager

1. Go to Google Tag Manager, click on Variables, and in the User-Defined Variables block, click New.
2. Click on the Variable Configuration block and select the variable type Data Layer Variable under Page Variables.
3. Enter the variable name (this must exactly match the variable name sent to the dataLayer in step 1), for example, “NinjaFormID” or “NinjaFormTitle”. At the top, enter a name that is easy to recognize in Tag Manager (e.g. “DLV – NinjaFormID”). DLV stands for Data Layer Variable.
4. Click Save.

Repeat this process for additional variables, such as “NinjaFormTitle” or any others you are sending.

Step 4: Create an Event Tag in Google Tag Manager

You likely already have a tag created in Google Tag Manager. If so, focus on the steps where you add an “Event Parameter”.

1. Go to Google Tag Manager, click on Tags, and then click New.
2. Click on the Tag Configuration block and select the tag type Google Analytics: GA4 Event.
3. At the top, enter a name that is easy to recognize within GTM (e.g., “GA4 – Event – form_submission”).
4. Under Configuration Tag, select the GA4 tag to which you want to send the event.
5. Enter an Event Name. This is the event name that you will also use in GA4. Avoid spaces (use underscores instead).
6. Add an Event Parameter under “Event Parameters”. Add a new row with the name: “NinjaFormID”. Select the variable “DLV – NinjaFormID” as the value. Never use spaces in parameter names.
7. Optionally, add a second parameter with the name: “NinjaFormTitle”. Select the variable “DLV – NinjaFormTitle” as the value.
8. At the bottom, select the trigger “Custom – ninjaFormSubmission”.
9. Click Save in the top-right corner. Don’t forget to publish the changes in Google Tag Manager.

Note: These parameters will not yet appear in GA4. To make them available, you need to create a custom dimension in GA4.

Step 5: Create an Event Parameter / Custom Dimension in GA4

1. Go to your GA4 property and navigate to Configure > Custom Definitions.
2. Click the blue button Create Custom Dimensions.
3. Fill in the four fields carefully:
   • Dimension Name: Used only within GA4 (for organization/reporting purposes).
   • Event Parameter: Must match exactly the event parameter sent from Google Tag Manager.
   • Scope: Select Event.
   • Description: Optional.
4. Click Save.