Custom Channel Grouping Builder for GA4

How to plan a GA4 custom channel grouping

A GA4 custom channel grouping sorts your traffic into channels you define, on top of Google's default ones. The hard part is not the regex — it's the order, because Google's custom channel groups page says the first matching channel wins. This builder writes the conditions, puts each new channel in a safe position and shows where your real traffic would land.

1. Pick the channels to add. Tick AI assistants, the paid social platforms you buy ads on, or brand search. Each comes with conditions built from Google's own lists and patterns.
2. Add your own channels. One line per channel: name, dimension, values and how to match. You can use Campaign id, Campaign name, Default channel group, Manual ad content, Medium, Source, Source platform.
3. Paste some traffic. Copy Session source / medium rows from Reports › Acquisition › Traffic acquisition. The table shows each row's default channel next to its channel in your new group.
4. Read the warnings. If a test row matches a new channel but an earlier channel takes it, the tool tells you which one to move.
5. Copy the set-up sheet. It lists every channel, condition and regex in order, ready to follow in GA4 Admin.

What to do next in GA4 Admin

1. Create the group. In Admin › Data display › Channel groups, click Create new channel group and give it the name from the set-up sheet. It starts as a copy of the default group.
2. Add each new channel. Click Add new channel, name it, click + Add condition group, choose the dimension and paste the value or regex from this page. Click Save channel.
3. Reorder. Open Reorder, drag each new channel to the position in the sheet and click Apply. Then save the group.
4. Check a report. In Traffic acquisition, change the primary dimension to your new group. Because custom groups are retroactive, last month's data shows in the new channels right away.
5. Make it the default if you like. Any custom group can be set as the property's primary channel group from the Channel groups list (pencil icon). New data then uses its rules.

Common custom channel group problems

GA4 custom channel group not working

Most often the channel is simply in the wrong place. A new channel for Meta ads below Paid Social, or a partner channel below Referral, never gets a visit. Move it up and the data appears — for past dates too.

GA4 ChatGPT and Perplexity traffic in Referral

GA4's own AI Assistant channel only covers referrers on Google's list, which Google doesn't publish. Other AI tools still arrive as referrals. A custom AI channel with a source pattern catches them, as long as it sits above Referral.

Paid social split shows nothing

The platform channels sit above Paid Shopping on purpose: Paid Shopping takes every paid click from a campaign whose name contains “shop” or “shopping”, so a Meta shopping campaign would never reach a channel placed lower. They need a source on Google's social list (such as facebook.com) or, for Meta, a site_source_name value like ig or msg, and a paid medium. Links tagged utm_source=meta or utm_medium=social_paid don't qualify. Fix the tags with the UTM tools linked below, or add those values to your own channel.

Custom channel group source regex too broad

A pattern like .*ai.* also matches “mail”, “retail” and “email”. Use full source names, as the AI list here does, and test with real rows before you save.

Missing in BigQuery or audiences

Custom channel groups are not in the BigQuery export, and edits apply only going forward for audiences. Build reports on them in GA4 itself.