Custom Definitions in Google Analytics 4

This article introduces the Custom Definitions of GA4. There are three Custom Definitions, namely:

• Custom dimensions: Dimensions describe data. They are usually in units of rows in your report. For example, dimensions can describe what they are, such as what keywords come from, what city the visitor comes from, and which pages are visited.
• Custom metrics: metrics are measurement data. metrics are used to quantify dimensions. Indicators are how many answers there are, or how long they last, or how many people visit, or how long visitors stay on the page, etc.
• Calculate metrics: You can create your own metrics based on existing metrics

Custom dimensions

Custom dimensions can be divided into:

User-scoped custom dimensions

User-scoped custom dimensions enable you to report on custom user properties. When you add a custom user property into your website or app code, these custom dimensions unlock the ability to dissect and understand the user-specific data.

Read more: Get User’s IP in Google Analytics 4

Event-level custom dimensions

Event-scoped custom dimensions enable you to report on custom event parameters, which measure details about user actions captured through an event. Whether you’re identifying clicked links or video engagement, adding a custom event parameter to your recommended events or custom events allows for in-depth analysis of these interactions.

Read more: Custom Events in Google Analytics 4 （dataLayer.push method）

Product-level custom dimensions

The product type is only available in e-commerce and is only used for e-commerce to add product information. By default, e-commerce only has a few dimensions, which are generally sufficient, such as:

dataLayer.push({
  "event": "removeFromCart",
  "ecommerce": {
    "currencyCode": "USD",
    "remove": {
      "products": [{
        "id": "bc823",
        "name": "Fuelworks T-Shirt",
        "price": "92.00",
        "brand": "Fuelworks",
        "category": "T-Shirts",
        "variant": "red",
        "position": 0,
        "quantity": 1
      }]
    }
  }
});

If you want to add “color: “black”, the details are as follows:

dataLayer.push({
  "event": "removeFromCart",
  "ecommerce": {
    "currencyCode": "USD",
    "remove": {
      "products": [{
        "id": "bc823",
        "name": "Fuelworks T-Shirt",
        "price": "92.00",
        "brand": "Fuelworks",
        "category": "T-Shirts",
        "variant": "red",
        "color": "black",
        "position": 0,
        "quantity": 1
      }]
    }
  }
});

Custom metrics

Numeric parameters are custom metrics and only have event-level scope

Read more : Introduction to Event Parameters in Google Analytics 4

Calculate metrics

Calculate metrics enable you to combine one or more existing metrics and/or custom metrics to produce a new and potentially more valuable metric.