ga4-custom-dimensions

Custom dimensions and metrics in GA4 are created by registering event, user, or item-scoped parameters in GA4 Admin after emitting them in your tracking code. Register parameters by scope type, then verify population in DebugView before using them in reports within standard quota limits.

Event scope captures data specific to individual events, user scope persists across all sessions for a user, and item scope applies to e-commerce items within transactions. Choose scope based on whether the data varies per event, per user, or per product.

Custom dimensions require 24–48 hours to populate after registration and parameter emission. Verify parameters are firing correctly in DebugView, confirm registration in GA4 Admin with matching names and scopes, and check that quota limits haven't been exceeded.

Register custom metrics in GA4 Admin by mapping event parameters to metric definitions with appropriate scopes and calculation methods. Emit the numeric parameters in your tracking events, then verify population in DebugView before reporting.

Custom dimensions are property-specific and must be registered separately in each GA4 property's Admin panel. Each property maintains its own scope configuration and quota allocation for custom dimensions and metrics.

Document dimension naming conventions, scope assignments, and ownership; monitor quota usage; establish review procedures before registration; and plan parameter lifecycle to avoid exceeding GA4's custom dimension and metric limits.