How do I use event parameters effectively in GA4?

Applies to: Google Analytics 4 (GA4)
Last updated: May 2025

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Problem

You want to pass additional context with events—such as product name, button label, or form type—but aren’t sure how to structure or use event parameters in GA4.

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Solution

GA4 allows you to send up to 25 parameters per event to capture extra information. These parameters help you understand event context, build reports, define audiences, and create custom dimensions.

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Step-by-Step Guide

1. Understand Default vs. Custom Parameters

GA4 has some recommended parameters for standard events (like value, currency, items), but you can also create custom parameters for your unique needs.

Examples:

• button_text
• form_type
• page_section
• cta_position

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2. Send Parameters with an Event

Using gtag.js:

gtag('event', 'form_submit', {
  form_type: 'contact',
  button_text: 'Send Message'
});

Using Google Tag Manager:

1. Open your GA4 Event tag
2. In the Event Parameters section:
   • Add key-value pairs:
     • Name: form_type, Value: 'contact'
     • Name: button_text, Value: 'Send Message' or use GTM variables
3. Save and publish

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3. Register Custom Parameters as Custom Dimensions (If Needed)

If you want to use a parameter in reports:

1. Go to Admin > Custom Definitions > Create Custom Dimension
2. Name it (e.g., “Form Type”)
3. Set the scope to “Event”
4. Use the exact parameter name (e.g., form_type)
5. Save

Only registered parameters will appear in Explorations or standard reports.

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4. Use Parameters in Reports and Audiences

• Use them as filters or segments in Explorations
• Include them in event tables for granular analysis
• Use them to define audiences, e.g., users who submitted a form where form_type = 'demo'

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Best Practices

• Be consistent with parameter names and values (use lowercase, underscores)
• Keep parameter values short and descriptive
• Use recommended parameters when tracking standard events (for consistency)
• Don’t pass PII (e.g., names, emails) in parameters

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Notes

• GA4 allows up to 25 parameters per event
• You can create up to 50 custom dimensions per property
• Custom parameters are not retroactive—data only appears after registration