Default metrics in GA4 don’t show what matters. You need to know if users complete onboarding, use key features, or take action after reading your content. Sadly, GA4’s setup feels too complex and was not built for SaaS.

I’ve worked through those same frustrations and found a simpler way to get the insights that move the needle.

In this guide, you’ll learn how to create custom event tracking in GA4 using Google Tag Manager. I’ll also show you how to choose the right events and use the data to improve acquisition, retention, and product adoption.

SaaS growth depends on what users do after they land. The default GA4 metrics tell you where users came from or how long they stayed. But they don’t reveal whether those users found value, signed up, or engaged with your product in meaningful ways.

Here’s the gap between what GA4 tracks by default and what SaaS teams actually need:

Use custom events to:

• Track high-impact user actions that drive growth
• Identify where users drop off in key journeys
• Improve product and website experiences based on user behavior

To set up custom events, you’ll need a Google Tag Manager (GTM) account connected to your GA4 property. Once that’s in place, follow these steps:

• Open GTM and create a new tag

• Select “GA4 Event” to send custom event data to your GA4 property.

• Choose your event name

 Use a short, clear name that reflects the action you're tracking. For example: sign_up, demo_request,  x_feature_use 

• Set up a trigger to tell GTM when to fire your event

• Use standard triggers like button clicks if they meet your needs. These are quick to set up and don’t require technical configuration.

• Use custom triggers for more complex actions, such as tracking onboarding steps, different plan selections, or payment confirmations. In these cases, push data to the GTM data layer to fire the event accurately.

• Test your setup in Preview mode

Always test before publishing. Simulate the action in GTM’s Preview mode and check the debugger console to confirm your event fires as expected. If it doesn’t, revisit your tag and trigger configuration.

• Publish and monitor

Once testing confirms it works, publish your changes and monitor the event flow in GA4’s real-time reports to verify your data is coming through correctly.

GA4 allows you to track almost anything, but that doesn’t mean you should track everything. The key is to focus on the questions you want your data to answer.

Track how users engage with your content, landing pages, and key elements. This helps you identify what drives attention, where users drop off, and how to improve the acquisition funnel.

Custom events to track:

1.sign_up: Measure which pages convert visitors into product users.

To do this:

• Go to Reports > Life cycle > Engagement
• In the default event report, use the search bar to locate the sign_up event
• Click the icon next to the Event name dimension
• Add Page path/screen class from the Page / Screen category as a secondary dimension

It shows the specific URLs or app screens driving signups, and you can use this data to identify your most effective entry points.

2. subscribe-newsletter: Identify which pages collect the most email signups 

Follow the same steps as with the sign_up event:

• Go to Reports > Lifecycle > Engagement
• Search for the subscribe_newsletter event
• Click the icon next to the Event name dimension
• Add Page path/screen class as a secondary dimension

This shows which pages drive the most newsletter subscriptions, so you can double down on what works and adjust underperforming content.

3. blog_shares: Discover content that gets the most social shares 

Use the Page path/screen class dimension to see which blog posts get the most shares on social platforms and which ones fall short. This information helps you refine your content strategy based on engagement.

4. clicks_on_in_content_links: Optimize navigation based on user behavior

Use the Page path/screen class dimension to see which pages have low link engagement. If users aren’t clicking in-content links as expected, adjust the layout, placement, or wording to improve navigation and guide users more effectively through key journeys.

Track how and where potential users show buying intent to optimize landing pages and improve conversion points.

Custom events to track:

5. contact_request: See which pages prompt users to reach out to your team

Use the Page path/screen class dimension to identify high and low-performing touchpoints, then adjust page content or layout to improve lead flow.

6. button_clicks: Test button placement, text, and design based on user actions

To filter by user segments:

• Click the “+” icon next to the Event name
• Select Audience name under the User category

This helps you check if specific audiences are engaging with buttons as intended.

If you haven’t created audiences yet:

• Go to Admin > Data display > Audiences
• Create a new audience using a prebuilt audience suggestion or define your criteria

7. feature_demo: Track where demo requests originate and which features drive them

Filter this custom event with the page path and screen class to track where demo requests originate and which features drive them. 

Tracking feature demos help you understand which pages generate quality leads so you can replicate the strategy for other pages.

8. live_chat_interactions: Identify pages that prompt users to seek help

Tracking live chat interactions help you determine pages that need to be more helpful.

Strong navigation keeps users engaged and moving through your site. Tracking how users interact with internal links helps you identify and fix weak points in your site structure.

Custom events to track:

9. navbar_click: See which navigation links get the most clicks

Discover which links in the navigation menu get the most clicks and which pages drive the clicks. Use the Page path/screen class dimension to spot patterns and decide where layout or link placement needs improvement.

10. cta_click: Access CTA performance

Evaluate your CTAs' performance by applying the Page path/screen class dimension. Use this data to adjust text, design, or placement on underperforming pages.

11. footer_link_click: Understand which footer navigation links perform well

Set a custom event for each footer link, and use Page path/screen class to assess performance. Next, replace low-performing links and move high-value ones into more prominent positions in the layout.

Tracking feature usage helps understand what users value most and which resources drive feature usage.

12. Feature-based custom events (like used_feature_x)

Track specific features users engage with, like export_html or invite_teammate.

To analyze feature usage:

• Use Page path/screen class to find the pages driving engagement
• Use Landing page + query string to identify entry points for feature adoption

The insights reveal which guides or pages perform well and which need optimization.

Go deeper than standard reports with Path exploration in GA4’s Explore tab. Create advanced exploration reports to gain detailed insights about your customers' journey. 

For example, in the image above, you can see one of the custom reports I created using GA4’s Path exploration technique in the Explore tab. It visualizes how organic traffic navigates through specific pages before users trigger the “subscribe-newsletter” custom event.

To create a similar report:

• Go to Explore and choose the Path exploration template
• Click Start over to define a custom starting or ending point
• Click a data point to view the users' next step after your starting point or previous steps before your ending point
• Drag one or more segments from the Variables column to the Segment section to filter users
• Set the time range you want to inspect

This custom event tracking helps SaaS businesses understand what content drives engagement and conversions.

Here are some tips to improve custom tracking in GA4:

• Prioritize high-value actions: Focus on events directly impacting growth, revenue, or retention. Avoid cluttering your setup with low-impact interactions.
• Test before and after publishing: Always validate your configuration in GTM’s Preview mode and confirm events are firing as expected. Clean data starts on day one.
• Make your tracking shared knowledge: Document and share what each event means. The insights lose their value if you’re the only stakeholder who understands the data.

PS: Check out my spreadsheet to see more custom event examples.

Custom event tracking gives you real insight into how users engage with your product, not just that they visited. It helps you understand what’s working, where users drop off, and how to improve their experience.

With the right setup, custom events become a reliable tool for optimizing funnels, increasing feature adoption, and supporting smarter decisions across teams.

Start today by identifying key user actions, setting up custom events in Google Tag Manager, and using the data to improve acquisition and retention.