Guide

GA4 UTM tracking without the folklore

Google Analytics 4 still drinks UTM parameters. It just serves them in new glasses labeled Session and First user. This page is what happens after the click — collection, session vs first user, and why (not set) appears. Where to click in the UI is how to see UTMs in GA4.

Collection behavior, not a report recipe. Last reviewed August 2026.

What GA4 reads on the landing page

When a page loads with UTM query parameters, the Google tag stores campaign dimensions on that session. You do not enable a secret “UTM mode.” You do need the tag to fire on that first page. If a redirect strips the query string before the tag runs, GA4 never sees the love letter you wrote.

Standard keys: utm_source, utm_medium, utm_campaign, utm_id, utm_term, utm_content. Additional keys: utm_source_platform, utm_creative_format, utm_marketing_tactic.

Session vs first user

GA4 keeps both session acquisition and first user acquisition. Session fields describe this visit. First user fields describe how the user originally arrived — useful for “which campaign created the account,” less useful for “which email drove this week’s revenue.” Know which one you are charting before you declare an email program dead.

Channel groups are picky eaters

Default channel grouping is not a vibe check. It matches source and medium against rules. Paid Search likes cpc / ppc plus a search engine source. Email likes email. Paid Social likes paid_social (and similar). If you send utm_medium=social-ads-cool, do not be shocked when the session sits in Unassigned like it missed the seating chart.

This toolkit’s builder shows a likely group. It is a hint, not a legal filing. Confirm in your property after a test click.

Why you see (not set) and Unassigned

• (not set) on campaign usually means the URL had source/medium but no utm_campaign, or a tag fired without campaign fields.
• Unassigned usually means the medium is not in the default rules.
• Direct often means the click arrived without parameters — QR codes with naked URLs, apps that strip queries, or people typing the domain because they liked you enough to remember it.

Auto-tagging and manual UTMs

Google Ads auto-tagging uses the gclid click identifier. GA4 can import Google Ads data when accounts are linked. Manual UTMs on Google Ads are optional spice, not a replacement for linking. If you add both, keep values consistent so you do not create a shadow campaign named slightly differently. Details live in UTM for Google Ads.

What this page does not cover

Menu paths and Explorations: how to see UTMs in GA4. Mediums that fail grouping: Unassigned. Ads Manager totals that will never equal sessions: ads vs GA4.

A test ritual that takes four minutes

1. Build a link in the UTM builder.
2. Open it in an incognito window.
3. In GA4, use DebugView or wait for the standard reports (they are not instant; analytics is many things, “live sports” is not one of them).
4. Confirm source, medium, campaign, and channel group.

If those four minutes feel like overhead, compare them to a quarter spent explaining why LinkedIn is listed four ways.