UTM Parameters Explained — How to Track Campaign Links in GA4
Updated October 2026 · 5 min read
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UTM parameters (Urchin Tracking Module) are tags appended to URLs that tell analytics platforms exactly where a visitor came from and which campaign drove the click. Without them, Google Analytics attributes many paid and email visits as "Direct" — making it impossible to measure campaign ROI accurately.
The 5 UTM Parameters
| Parameter | Required? | What it tracks | Example value |
|---|---|---|---|
| utm_source | Yes | Where the traffic comes from | google, newsletter, facebook |
| utm_medium | Yes | The marketing channel | cpc, email, social, banner |
| utm_campaign | Yes | The campaign name | black_friday_2026 |
| utm_content | Optional | Ad variant or link (A/B testing) | blue_cta, hero_banner |
| utm_term | Optional | Paid keyword | best+crm+software |
What a UTM URL Looks Like
https://example.com/pricing/?utm_source=newsletter&utm_medium=email&utm_campaign=oct_launch&utm_content=cta_button
Everything after the ? is invisible to the visitor but readable by Google Analytics 4. GA4 groups sessions by source/medium automatically — you see "newsletter / email" as a channel in your reports.
UTM Naming Best Practices
- Use lowercase: GA4 is case-sensitive. "Email" and "email" appear as two separate sources. Always use lowercase.
- Use underscores, not spaces: Spaces become
%20in URLs. Useblack_fridaynotblack friday. - Be consistent: Define your taxonomy once and document it. "fb" vs "facebook" vs "Facebook" will fragment your data.
- Never UTM-tag internal links: Adding UTM parameters to links between your own pages resets the session source, breaking attribution. UTM tags are for external links only.
- Use a spreadsheet: Track every UTM-tagged URL in one place so your team reuses the same naming conventions.
Common utm_medium Values by Channel
| Channel | utm_medium | utm_source example |
|---|---|---|
| Google Search Ads | cpc | |
| Email newsletter | mailchimp | |
| Facebook/Instagram Ads | paid_social | |
| Organic social | social | |
| Partner / affiliate | affiliate | partner_name |
| Display banner ads | display | gdn |
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