What is a Secondary Dimension in Google Analytics?
A secondary dimension in Google Analytics 4 is an attribute that splits your primary dimension or attribute into smaller groups.
Primary Dimension
If you are looking to split your website traffic into countries, then the main attribute you are looking for is “country”. That is what Google Analycis 4 (GA4) considers a “dimension”. For the purposes of your report, country will be your “primary dimension”.
Secondary Dimension
Once you split your website traffic by country, you might want to break your traffic further into smaller buckets by region, for example.
What you can do in your report is, select “country” as your primary dimension and “region” as your secondary dimension.
Full List of Google Analytics Primary and Secondary Dimensions
GA4 has a large number of dimensions. Here are a few, based on traffic sources:
Dimensions
| Field name | UA Name | GA4 equivalent name |
|---|---|---|
| Full Referrer | ga:fullReferrer | pageReferrer |
| Campaign | ga:campaign | sessionCampaignName |
| Source | ga:source | sessionSource |
| Medium | ga:medium | sessionMedium |
| Campaign Code | ga:campaignCode | sessionCampaignId |
For a full list of the dimensions and metrics that the GA4 platform is offering to slice and dice your date, please visit their dimensions and metrics page here.
