Google Tag Manager Custom Event Trigger (Explained)

Have you ever needed to track specific user actions on your website that GTM doesn’t capture by default? That’s where Google Tag Manager Custom Event Trigger comes in, allowing you to track unique interactions like form submissions, button clicks, or video plays with the GTM data layer.

In this article, you’ll learn what a Custom Event Trigger is and how it works, along with step-by-step instructions to set up a GTM custom event trigger. We will also cover common use cases, best practices, troubleshooting tips, and ways to improve website tracking accuracy.

Let’s get started!

What is a Google Tag Manager Custom Event Trigger?

A Google Tag Manager (GTM) Custom Event Trigger is a type of trigger that activates a tag when a specific event, defined by you, occurs on your website or app. It listens for a “custom event” that you push into the GTM data layer. Unlike built-in triggers, which track predefined interactions like page views or link clicks, custom event triggers allow you to track specific user actions that GTM doesn’t automatically capture.

Here are some practical examples:

• Form submissions: Tracking Form submissions when a user completes a sign-up or contact form.
• Button clicks: Monitoring button clicks on call-to-action (CTA) buttons.
• Video interactions: Capturing video interactions, such as play, pause, or completion.
• Scroll depth: Tracking scroll depth to measure user engagement with long pages.

Custom event triggers in Google Tag Manager are essential because they allow businesses to track specific user interactions that standard GTM triggers might overlook. Businesses better understand how users interact with their websites by customizing tracking to capture actions like form submissions, button clicks, and engagement with interactive elements. 

This improved accuracy ensures that key behaviors are appropriately measured, leading to more effective website optimizations, better marketing strategies, and a more seamless user experience.

Setting Up Google Tag Manager Custom Event Trigger

Custom event trigger in Google Tag Manager (GTM) helps track user interactions that standard triggers don’t capture. Setting up a GTM custom event trigger involves defining an event, configuring conditions, and linking it to a tag. Here’s how to do it by following these steps:

Step 1: Log in to Google Tag Manager

• Log in to Google Tag Manager and open your container.

Step 2: Creating and Configuring a Custom Event Trigger

• Navigate to Triggers in the left-hand menu and click New.

• Click on the pen icon to trigger configuration.

• Choose Custom Event as trigger type.

• In the Event name field, enter the event name you used in your data layer push (in our case, ‘formSubmission’).
• Optionally, you can add trigger conditions to make the trigger more specific. For example, if you have multiple forms, you can use the formType or formLocation variables to only fire the trigger when the correct form is submitted. To do this, click Some Custom Events and add conditions such as “formType equals Contact Form.”
• Give your trigger a descriptive name (e.g., “Form Submission – Contact Form”).
• Click Save.

Step 3: Create or Modify a Tag to Use the Trigger

• Navigate to Tags in the left-hand menu and click New to create a tag.

• First, start the tag configuration by clicking on this trigger section.

• Choose Google Analytics as the tag type. 

• Then, choose the  Google Analytics: GA4 Event.

• Enter the Measurement ID for your GA4 property.
• If you see a disclaimer saying Google Tag Not Found, click Create Tag to generate a Google Tag.

• Create Google tag, configure it, and save it.

• Set the Event Name (e.g., “Form_Submit”) to match the trigger event.
• Configure additional variables like Event Category, Action, and Label using dynamic values from the data layer (e.g., {{formType}} and {{formLocation}}).

• In the Triggering section, select the custom event trigger you created earlier.
• Click on the save tab.

Step 4: Setup Testing, Publishing, and Viewing in GA4 Debug View

• Click the Preview button in GTM to enter preview mode.
• Visit your website and submit the form.
• In the GTM preview pane, check that the custom event trigger and your tag fired correctly.
• Open Google Analytics 4 and navigate to Admin >> DebugView to verify if the event appears in real time.

• If the test is successful, click Submit to publish the changes.

Common Use Cases for Custom Event Triggers in GTM

Below are the cases when you might need to use GTM custom event trigger to get a better understanding of user behavior:

1) Form Submissions

Tracking form submissions ensures you accurately measure lead generation and user engagement. GTM captures when a user submits a form by setting up a custom event trigger. A data layer push is added to the form’s submission function, sending an event like “form_submission”, which GTM detects and forwards to Google Analytics 4 (GA4) for reporting.

2) Button Clicks

For tracking “Add to Cart”, “Sign Up”, or “Submit” button clicks, a GTM custom event trigger listens for user actions on specific buttons. Instead of relying on standard Click Triggers, a Custom Event Trigger ensures tracking even when button elements change dynamically or use JavaScript-based interactions.

3) Video Interactions

Monitoring how users engage with videos helps analyze content effectiveness. Google Tag Manager trigger Custom event can capture when a user plays, pauses, or completes a video. Integrating with YouTube API or a video platform’s event listeners, you can push events like “video_play” or “video_complete” to GA4 for in-depth engagement analysis.

4) Scroll Depth Tracking

To measure content consumption, a GTM custom event trigger can fire when users scroll 25%, 50%, or 100% of a page. This helps evaluate user engagement on long-form content or landing pages. GTM listens for scroll depth thresholds and pushes corresponding events (e.g., “scroll_50”) to GA4.

5) E-commerce Tracking

E-commerce Tracking with product views, cart additions, checkout steps, or purchases is essential for online stores. GTM’s custom event triggers help you track key moments in a customer’s journey—like when they add a product to their cart, start checkout, or complete a purchase. Instead of just guessing what’s working, you get actual data. For example, when a user reaches the checkout page, a custom event like “begin_checkout” is sent to GA4, giving you clear insights into your conversion funnel.

Using custom event trigger in Google Tag Manager, you’re not just collecting numbers—you’re understanding how people interact with your site. This means you can make smarter optimizations, improve the user experience, and ultimately drive more conversions based on real-time data.

Best Practices for Creating GTM Custom Event Trigger

Setting up custom event triggers in Google Tag Manager (GTM) requires careful planning to ensure accurate tracking and maintain a well-structured setup. Follow these best practices to avoid common mistakes and optimize your event tracking process.

1) Use Clear and Descriptive Naming Conventions

Naming your custom events properly ensures clarity in reports and makes debugging easier. According to the naming conventions, use descriptive, camelCase or snake_case formats, such as:

• formSubmitted instead of form1
• productAddedToCart instead of cartAction1
•  videoPlayed instead of videoEvt

Consistent and meaningful names help quickly identify events in Google Analytics 4 (GA4) and other tracking tools.

2) Keep Event Definitions Simple

Defining complex custom events with unnecessary conditions can make debugging difficult. Instead, focus only on essential user interactions to keep event triggers simple. To maintain clarity, break multiple conditions into manageable triggers instead of combining them in a single trigger.

3) Test Your Triggers Before Publishing

Before publishing, always test custom event triggers using GTM’s Preview Mode and GA4 DebugView. This ensures that events fire correctly and prevents tracking failures due to misconfigured triggers. Skipping testing may result in missing valuable data.

4) Use Consistent Event Naming Across Triggers

Maintain uniform event names across your GTM setup to avoid confusion. If you use “add_to_cart” in one trigger and “productAdded” in another, tracking inconsistencies can arise in GA4. Standardizing event names improves data organization and reporting accuracy.

5) Avoid Overloading the Data Layer

Adding too many custom events to the dataLayer can slow your website and create conflicts. Only push essential data needed for tracking, such as:

• Form submissions
• Checkout steps
• Significant user interactions (e.g., video plays, button clicks)

Overloading the data layer with excessive events can lead to performance issues and tracking errors.

6) Double-Check Event Names to Avoid Typos

Even small event name typos can break tracking. In GA4, “form_submit” and “formSubmit” are treated as two different events. To prevent such issues, copy-paste event names from the data layer into GTM configurations instead of manually typing them.

7) Avoid Creating Too Many Triggers

Creating multiple triggers for similar actions makes GTM cluttered and harder to manage. Instead of setting up separate triggers for “buttonClick_1” and “buttonClick_2”, use a single trigger with additional conditions to handle both cases efficiently.

8) Ensure Event Names Are Consistent Across Platforms

If you send events from GTM to GA4, Facebook Pixel, or other tracking tools, ensure the event names remain consistent. Different names in different platforms can lead to data mismatches and reporting errors.

9) Never Skip Testing Before Going Live

One of the biggest mistakes is deploying custom event triggers without testing. Use GTM Preview Mode, GA4 DebugView, and Google Chrome Developer Tools to verify that the events fire correctly before publishing them. This prevents data loss and ensures accurate tracking from day one.

Following these best practices, you can create reliable, efficient, and well-structured custom event trigger in Google Tag Manager. This will improve data accuracy and streamline tracking across your analytics setup.

Debugging and Troubleshooting Google Tag Manager Custom Event Triggers

The first step is setting up a custom event trigger in Google Tag Manager (GTM). Ensuring they fire correctly is crucial for accurate tracking. GA4 Debugging helps identify misconfigurations, missing event data, and other issues affecting your analytics setup.

1) Use GTM Preview Mode to Test Triggers and Tags

Before publishing changes, test your custom event triggers using GTM’s Preview Mode. This lets you see how events fire in real time and verify whether your tags work correctly.

How to Use GTM Preview Mode:

1. Open Google Tag Manager and click Preview in the top-right corner.

2. Enter your website’s URL and click Connect. This opens a debug session.

3. Perform the action that should trigger the event (e.g., submit a form or click a button).
4. Check if your event appears under the Summary section in the Tag Assistant window.
5. Expand the event to see which tags fired and whether your custom event trigger worked as expected.

If Google Tag Manager is not working, check the detailed guide on how to fix Google Tag Manager Preview Mode not working. 

2) Check the Data Layer for Event Information

If a trigger isn’t working, inspect the data layer to confirm the event is being pushed correctly.

How to Inspect the Data Layer:

1. Open Google Chrome Developer Tools (Press F12 or right click >> inspect).

2. Go to the Console tab and type “window.dataLayer”.
3. Press Enter to view the list of events stored in the data layer.
4. Look for the custom event name and check if it appears as expected.
5. Ensure that event properties (e.g., form type, button ID) are present and correctly formatted.

If the event is missing, verify that your website is pushing it correctly using window.dataLayer.push().

3) Common Issues and How to Fix Them

There are the following common issues in debugging:

Triggers Not Firing

• Ensure that the event name in the trigger matches the data layer event exactly (case-sensitive).
• Check trigger conditions (e.g., page path, button ID) to ensure they aren’t too restrictive.
• Use GTM Preview Mode to confirm whether the event appears in the debug console.

Incorrect Event Names

• Double-check event names in the data layer and GTM trigger settings.
• Use copy-paste instead of manual typing to avoid typos.

Conflicts with Other Tags

• If multiple tags fire on the same event, check if there are duplicate event listeners.
• Use tag sequencing in GTM to control the order in which tags fire.

Google Tag Not Found Error

• If GTM displays a “Google Tag Not Found” warning, first create a new Google Tag in the Tags section before configuring event triggers.

Events Not Appearing in GA4

• Check if the Measurement ID in GTM matches the one in GA4.
• Wait a few minutes, as GA4 sometimes delays event processing.
• Open GA4 DebugView (Admin >> DebugView) to confirm the event’s receipt.

Following these debugging steps, you can identify and resolve issues with Google Tag Manager custom event triggers, ensuring that your tracking remains accurate and reliable.

Enhance Your Google Tag Manager Setup with Analytify

Google Tag Manager (GTM) simplifies event tracking, but analyzing the collected data in GA4 can be challenging. Analytify integrates seamlessly with GA4, making it easier to track, visualize, and analyze custom events triggered via GTM—all without needing complex configurations or coding.

Key Features of Analytify for GTM & GA4 Integration

• Automated Event Tracking Detects and records GA4 and GTM custom events without manual setup. Analytify automatically recognizes user interactions such as clicks, form submissions, and video plays, ensuring you don’t miss any key data.

• Real-Time Event Monitoring: View event interactions as they happen, ensuring instant insights. This feature helps you track user actions in real-time, enabling quick optimizations and troubleshooting of tracking issues.

• User-Friendly Dashboard: Presents event data in an easy-to-understand format, eliminating the need to navigate GA4’s complex reports. Instead of dealing with GA4’s overwhelming interface, Analytify directly provides simplified, visual reports in WordPress.

• Custom Event Reporting: Event tracking addon tracks key user interactions, including form submissions, button clicks, video plays, and e-commerce actions. This feature helps marketers analyze how users engage with their website and make data-driven improvements.

• E-commerce Event Tracking: This feature captures product views, add-to-cart actions, purchases, and checkout steps. With the Woocommerce tracking add-on, you can measure customer journey performance and optimize for higher conversions.

• Conversion Performance Analysis: Want to know which actions lead to conversions? Analytify helps you track and analyze custom events, giving you a clear picture of what’s working and needs improvement. By understanding which events drive results, you can fine-tune your marketing strategies for better engagement and higher conversions.
• Seamless GA4 Data Synchronization: Ensures accurate reporting by pulling event data directly from GA4 into Analytify’s dashboard. This feature eliminates discrepancies between GA4 and WordPress, offering a single reliable source for event tracking.

With Analytify’s GA4 integration and Event Tracking Addon, you better understand user behavior, optimize your marketing efforts, and enhance your website’s overall performance. 

GTM Custom Event Trigger FAQs

Final Thoughts: Google Tag Manager Custom Event Trigger

In conclusion, setting up Google Tag Manager trigger custom event is a powerful way to track user interactions beyond standard triggers. Businesses can gain deeper details into user behavior by defining specific events, configuring triggers, and linking them to relevant tags. 

Whether tracking form submissions, button clicks, video engagement, or e-commerce actions, custom event triggers ensure accurate data collection for better decision-making. Following best practices such as using clear naming conventions, testing thoroughly, and maintaining consistency across platforms helps avoid common tracking errors. 

Businesses can use Google Tag Manager Custom Event Trigger and its debugging tools to refine their event tracking and get the most value from their analytics.

However, if you encounter issues with GA4 Debug View not working, check our detailed guide to resolve common problems effectively.

If you have any questions about GTM custom event trigger, feel free to share them in the comments!