GA4 Channel Checker: Find Your Default Channel Group
See which GA4 default channel a source and medium land in, and the rule that decides it, before a campaign ends up in Unassigned. Runs in your browser.
How to use this tool
Enter the source and medium
Type the utm_source and utm_medium you plan to use, such as facebook and paid_social. Values are compared case-insensitively, as GA4 does.
Add the campaign name if relevant
The campaign name only matters for two channels: it decides Cross-network, and a name mentioning shopping moves paid traffic into Paid Shopping.
Read the result and the reason
The result card names the channel and the rule that matched. If it says Unassigned, pick a medium from the table that GA4 recognises.
Explore the rule table
Click any example in the table to load it into the fields and see how a change to the source or medium moves the visit from one channel to another.
Frequently Asked Questions
What is a GA4 default channel group?
It is the dimension GA4 uses to group traffic into broad channels such as Organic Search, Paid Social, Email and Referral. GA4 assigns it automatically from each session's source, medium and campaign name using fixed rules, and it drives the traffic acquisition report most people read first.
Why is my traffic Unassigned in GA4?
Unassigned means the source and medium matched none of GA4's channel rules. The usual cause is a custom medium, such as utm_medium=facebook, newsletter or offline. Change the medium to one GA4 recognises, such as paid_social, social, email or referral, and new visits are classified correctly.
What medium should I use for paid social ads?
Use a medium that matches GA4's paid pattern, such as paid_social, paid or cpc, together with a social network as the source, such as facebook, instagram, linkedin or tiktok. That combination lands in Paid Social. The same source with medium social lands in Organic Social instead.
Does the campaign name affect the channel?
Only in two cases. A campaign name containing cross-network is filed as Cross-network, and one containing shop or shopping turns paid traffic into Paid Shopping and unpaid traffic into Organic Shopping. For every other channel only the source and medium matter.
Can GA4 reclassify old traffic after I fix the medium?
No. The default channel group is set when the data is processed, so sessions already recorded as Unassigned stay that way in standard reports. Fixing the UTM values corrects new traffic from that point on. A custom channel group can regroup historical data in explorations.
How accurate is this checker?
It applies GA4's published rules in Google's order, including its regular expressions for paid mediums and shopping campaigns. Google matches sources against lists of several hundred domains; this tool includes the common names people use in utm_source, so an unusual source may classify differently in your property.
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