Your source/medium and campaign data can be very granular. Your report might have dozens (or for a large website, hundreds) of rows, which can be hard to interpret.

Channel groupings are a way to simplify this view, by putting different marketing channels into buckets. A channels report will not have too many rows and is therefore suitable for an exec summary (or a starting point) – however detailed analysis might require you to look at source/medium.

Google has a default channel grouping which you can’t edit. You can find the definitions of each channel here. You can also create your own custom channel groups and use those in reporting side by side with the default one.

It’s a good idea to look at these rules because they are often based on UTM tagging conventions, and you may want to have your own UTM tagging process ensure that GA4 classifies your traffic into the appropriate channel. For example, for the Email channel, GA4 expects medium to be set to “email”, so if you’re using something like “enewsletter” it may be worth changing.

For each channel grouping, there are 3 separate dimensions. Below is the example for the default channel group:

• Default channel group
• First user default channel group
• Session default channel group

These mean slightly different things for which see this earlier post in the sequence.

When you create your own channel grouping, you get to create rules for each channel. These are applied sequentially, so each session or event is classified according to rule 1, then rule 2 if rule 1 doesn’t match etc. You can use this to simplify the rule clauses. For example, these 2 rules will classify traffic as Google organic or Google paid:

1. Google paid: source = google and medium = cpc
2. Google organic: source = google (note we don’t need to include anything else because this rule is the 2nd in the list so it will only be evaluated if the above rule fails)

Typically rules will be based on source, medium and campaign but they can be based on other dimensions too. There are many use cases but one example might be grouping organic SEO traffic that landed on your homepage together with paid branded keywords since for many brands, traffic landing on your homepage is likely to have searched for your brand.