Custom Dimension (GA4)

A custom dimension in Google Analytics 4 makes certain additional descriptive data available for analysis beyond the standard dimensions provided by the product. For example, a service website might collect a nonpersonal service-category value on a quote-request event and register an event-scoped custom dimension using that event parameter. The parameter carries the data; the custom dimension makes the relevant values available for reporting. Not every parameter needs a custom dimension, so check for an existing predefined dimension first. For an event-scoped custom dimension, the selected event parameter must actually be collected, and Google notes that it can take 24–48 hours after data collection and dimension creation before it becomes available in reports. Dimensions do not collect missing information by themselves, and private customer details should not be sent to Analytics.