Google Analytics 4 (GA4) now supports custom event data import, enabling users to combine standard fields and event-scoped custom dimensions to integrate and analyze imported event metadata with existing Analytics data. This feature allows for the creation of custom reports using data that you’ve collected outside of GA4, providing a more comprehensive view of Analytics data and imported event metadata.

Key Features

• Custom Event Data Import: Allows importing data collected outside GA4 using standard fields and event-scoped custom dimensions as join keys.
• Custom Reports: Enables the creation of custom reports to view imported data alongside standard Analytics data.

How It Works

1. Setup: Requires setting up event-scoped custom dimensions in GA4 property.
2. Data Upload: Data can be uploaded via CSV file or SFTP server.
3. Field Mapping: Fields in the imported data must be mapped to GA4 fields.
4. Data Availability: Uploaded data can take up to 24 hours to appear in reports, audiences, and explorations.

Steps to Import Data

1. Create Data Source: Select "Custom event data" as the data type as outlined in the data import guide.

2. Map Fields: After you select the option to upload data from a CSV file or SFTP server, you must add your mappings:
   • Key Fields Table: Add fields in GA4 to join imported data.
   • Import Fields Table: Select fields to include in the data via the join key.
3. Upload Data: After you upload your data, it can take up to 24 hours for Analytics to make that data available in reports, audiences, and explorations.

Data-Source Details

• Scope: Only event-scoped custom dimensions are supported.
• Key Fields: Up to two dimensions from categories like Platform, Stream ID, Page/Screen, etc.
• Import Fields: Up to ten dimensions from similar categories.

Notes and Limitations

• Unique Dimensions: All selected dimensions must be unique across key and import fields.
• Single Data Source: Only one data source is allowed for custom event data import.
• Event Naming Conventions: Typed-in event parameters must follow expected naming conventions.
• Deletion of Custom Dimensions:
  • If a custom dimension used as a key field is deleted, the import will fail.
  • If used as an import field, the import will continue, but the dimension will no longer be available in reporting.
• No New Events: Custom event data import cannot create new events.
• Type-in Event Parameters: These will not be surfaced in reporting unless associated with a custom dimension.

Visit the analytics help center to know more.