Custom Dimensions and Metrics in Google Analytics 4

Create dimensions and metrics from event parameters and user properties so you can easily access data in reports and explorations

Custom dimensions and metrics are dimensions and metrics that you create. They allow you to analyze data that is specific to your business needs. They're useful when you create custom event parameters or custom user properties.

How it works

When you create a custom dimension or metric, you provide the name of the custom event parameter or custom user property that Analytics should associate with the new dimension or metric. Analytics then populates the new dimension or metric with whatever value it collects from the corresponding event parameter or user property.

Benefits

Creating custom dimensions and metrics allows you to easily access and use your event properties and user properties. For example, without creating a custom dimension for your custom color event parameter, you won't be able to see the parameter values in reports or use them in audiences.

Best practices

Before you create custom dimensions and metrics, use the default dimensions and metrics.

If you have a standard property, do not create unnecessary high-cardinality custom dimensions. High-cardinality dimensions may negatively impact your reports and cause data to aggregate under the (other) row.

Example The following are examples of high-cardinality dimensions that aren't allowed or should be avoided:

• Using a custom dimension for a unique ID per user; instead, use the User-ID feature

  • Learn more about how to meet your use cases without creating a custom dimension for a user ID

• Using a custom dimension to send unique IDs per session, like a Session ID

• Sending a timestamp as a custom dimension

Lastly, registering a custom dimension for a parameter that is already a predefined dimension, such as the page and screen dimensions, or transaction ID, is not a best practice. It will not affect cardinality, but it will use one of your custom dimension quota.

Limits & caveats

If you reach any of the following limits, archive the custom dimensions or metrics you don't use to create new ones:

Note: You can send up to 27 item-scoped custom parameters from your website or app, of which you can configure 10 item-scoped custom parameters for standard properties and 25 for Analytics 360 properties. This gives you the flexibility to choose from a larger pool of parameters without having to retag.

To see the number of custom dimensions and metrics you've created:

1. In Google Analytics, click Admin.

2. Make sure you are in the correct account and property.

3. In the Property column, click Custom definitions.

4. On the top right, click Quota information.

Certain custom dimensions aren't available in your reports when combined with demographic information. You may experience thresholding or incompatibility constraints when requesting custom dimensions with demographic data.

Before you begin

You must have the Editor or Administrator role to create custom dimensions and metrics.

Create a custom dimension

1. In Google Analytics, click Admin.

2. Make sure you are in the correct account and property.

3. In the Properties column, click Custom definitions.

4. In the Custom dimensions tab, click Create custom dimensions.

5. Complete the following information:

   • Dimension name: Enter a unique name for the dimension. You can't use hyphens in the name, but you can use underscores and spaces instead.

   • Scope: Choose a scope for the custom dimension. Learn more

   • Description: Enter a memorable description for the custom dimension.

   • Event parameter/User property: Choose the source of data. Learn more

6. Click Save.

You will see a value of (not set) for a custom dimension in the first 48 hours.

Create a custom metric

1. In Google Analytics, click Admin.

2. Make sure you are in the correct account and property.

3. In the Properties column, click Custom definitions.

4. In the Custom metrics tab, click Create custom metrics.

5. Complete the following information:

   • Metric name: Enter a unique name for the metric. You can't use hyphens in the name, but you can use underscores and spaces instead.

   • Scope: You must create an event-scoped metric. Learn more

   • Description: Enter a memorable description for the custom metric.

   • Event parameter: Choose the source of data. Learn more

   • Unit of measurement: Choose the unit of measurement. Learn more

6. Click Save.

You will see a value of (not set) for a custom dimension for up to the first 48 hours.

Scopes

A custom dimension can have one of the following scopes:

A custom metric always has an event scope.

Units of measurement

When you create a custom metric, you can choose from the following units of measurement:

Source of data

As you create a custom dimension or metric, you will be asked to choose the event parameter or user property from which you want to derive data. The source of data for a custom dimension differs from the source of data for a custom metric.

You can enter the name of the event parameter or user property, or you can use the drop-down menu. You must wait up to 48 hours to see a new event parameter or user property in the drop-down menu.

Edit a custom dimension or metric

You must be an Editor or Administrator to edit custom dimensions or metrics.

1. On the left, click Admin > Custom definitions.

2. In the row for the dimension or metric, click > Edit.

3. Make the changes you want, then click Save.

Archive dimensions and metrics

Create more custom dimensions and metrics by archiving ones you don't use If you reach the limit on the number of custom dimensions or metrics you can create, you can free up space to create more custom dimensions or metrics by archiving the ones you don't use. You can always reuse the name of the dimension or metric after archiving it. Archiving a custom dimension or metric affects any audiences, explorations, segments, or custom reports that are based on or use the now archived custom dimension or metric.

Warning: This change can't be undone and the corresponding data can't be restored.

Archive custom dimensions and metrics

1. In the left navigation, click Admin.

2. In the Property column, click Custom definitions.

3. In the row for the custom dimension or metric, click > Archive.

4. Review the list of entities in Analytics (e.g., audiences, explorations) that use the custom dimension or metric.

5. Click Archive.