UTM builder with GA4 channel check
Messy UTMs are why GA4 reports half your paid social as "Unassigned". This builds consistent links, keeps platform macros intact, and tells you which GA4 channel each link will land in before you publish it.
How it is calculated
The builder adds utm_source, utm_medium, utm_campaign, utm_content, utm_term and utm_id to your link, keeps any query string and anchor already on it, and, if you leave clean naming on, converts values to lower case with hyphens. Platform macros such as {{campaign.name}} or {campaignid} are left untouched so the ad platform can fill them in.
The channel check applies a simplified version of GA4's default channel group rules to your source, medium and campaign. Paid channels need a paid medium (anything matching cpc, ppc, retargeting or starting with paid) and a source GA4 recognises.
How to use the result
Agree one naming convention across the team and agencies and keep it in a shared sheet; consistency matters more than the convention you choose. Use your recent links list to stay consistent across a campaign. For Google Ads, keep auto-tagging switched on; UTMs complement it for non-Google analytics tools.
Questions
What are UTM parameters?
UTM parameters are tags added to a URL, such as utm_source, utm_medium and utm_campaign, that tell analytics tools like GA4 where a visit came from. Source is the platform, medium is the type of traffic and campaign is the specific initiative.
Why does GA4 show my traffic as Unassigned?
Usually because the utm_medium or utm_source does not match GA4's default channel group rules. For example, utm_medium=paidsocial is recognised as paid, but utm_medium=meta-ads is not, so the session falls into Unassigned or Paid Other.
What UTM medium should I use for paid social?
Use a medium GA4 recognises as paid, such as paid-social or cpc, with a source it recognises as social, such as facebook, instagram or linkedin. That combination maps to the Paid Social channel.
Should UTMs be lower case?
Yes. GA4 treats Facebook, facebook and FACEBOOK as three different sources, which splits your reports. Lower case with hyphens instead of spaces is the safest convention.
Do I need UTMs on Google Ads if auto-tagging is on?
Not for GA4, which reads the gclid from auto-tagging. UTMs are still useful for other analytics tools, CRMs and server-side tracking that do not read gclid.
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