The UTM parameters GA4 reads
Google Analytics 4 still uses the five classic UTM parameters, and adds four more that map to their own dimensions. You do not need all nine on every link – source, medium and campaign are the essentials – but the extra fields make paid-media reporting and cost imports far easier.
| Parameter | GA4 dimension | Use it for |
|---|---|---|
utm_id | Session campaign ID | A stable ID that joins web traffic to cost data you import from non-Google ad platforms. |
utm_source | Session source | Where the click came from: google, facebook, newsletter. |
utm_medium | Session medium | The channel type: cpc, email, social, display. Drives the default channel group. |
utm_campaign | Session campaign | The promotion or initiative name. |
utm_content | Session manual ad content | Which ad, button or link variant was clicked. |
utm_term | Session manual term | Paid keyword or audience. |
utm_source_platform | Session source platform | The buying platform, e.g. search-ads-360, dv360 or a social ads manager. |
utm_creative_format | Session manual creative format | The ad format: video, carousel, native, display. |
utm_marketing_tactic | Session manual marketing tactic | Targeting approach: prospecting, remarketing, lookalike. |
Dimension names are shown as they appear in GA4’s session-scoped reports; GA4 also offers first-user versions of most of them.
See the GA4 channel before you publish
GA4 sorts every session into a default channel group – Paid Search, Organic Social, Email and so on – using fixed rules on source, medium and campaign name. A link tagged with a medium GA4 does not recognise, such as “newsletter” or “print”, matches none of those rules and is reported as Unassigned, which is the most common reason campaign traffic seems to vanish from channel reports.
As you type, the builder applies the same rules and shows the predicted channel with the reason it matched. If the prediction says Unassigned or Paid Other, change the medium (for example “email” instead of “newsletter”, or “paid-social” instead of “ads”) before the link goes live.
The full list of rules, with examples, is on the GA4 Channel Checker page.
Google Ads auto-tagging vs manual UTM tags
If your Google Ads account is linked to GA4 with auto-tagging switched on, every ad click carries a gclid and GA4 pulls campaign details from Google Ads automatically – you do not need UTM tags on those ads. Manual UTM tags are for everything else: Meta, LinkedIn, TikTok and Microsoft Ads, email, affiliates, influencers, QR codes and offline media. When a link has both a gclid and UTM values, GA4 gives the auto-tagged data priority by default.