What are UTM parameters?
Tags on the end of a campaign link that tell Google Analytics 4 where a visitor came from. Without them, most campaign traffic is reported as Direct or Unassigned.
Source, medium, campaign
The three required tags. utm_source is where the click came from, utm_medium is the channel type, utm_campaign names the initiative.
Term, content, id
Optional. utm_term for paid keywords, utm_content to tell creatives apart, utm_id so GA4 can match imported ad spend.
One spelling, lowercase
GA4 reports Facebook and facebook as two rows. Pick one spelling per platform, keep it lowercase, and never tag your own internal links.
Which GA4 channel will my link land in?
GA4 matches your source and medium against its channel rules. The builder above previews that assignment before you launch.
| utm_source | utm_medium | GA4 default channel |
|---|---|---|
| cpc | Paid Search | |
| organic | Organic Search | |
| cpc or paid_social | Paid Social | |
| social | Organic Social | |
| youtube | cpc | Paid Video |
| newsletter | ||
| any | display, banner, cpm | Display |
| anything unrecognised | media, paidsearch | Unassigned |
Frequently asked questions
What does UTM stand for?
UTM means Urchin Tracking Module. These parameters identify where traffic came from and how each campaign performs.
What is the difference between source and medium?
Source is where traffic came from. Medium is the type of channel. Example: source=google, medium=cpc.
Are UTM parameters case-sensitive in GA4?
Your reports are. GA4 shows values exactly as you type them, so Facebook and facebook appear as two rows. Google's channel grouping itself is not case sensitive, so both still reach Paid Social. Keep everything lowercase and the problem disappears.
How many UTM parameters should I use?
Use source, medium and campaign every time. Add term and content only when useful. Add utm_id when you need strict campaign IDs or GA4 cost-data import.
Should spaces be %20, a plus sign, or an underscore?
Either %20 or a plus sign is fine, and GA4 reads both as a space. What matters is that the words survive: deleting the spaces turns "growth marketing agency" into a different keyword. Underscores also work, as long as every person on the team uses them the same way.
Why does my traffic show as Unassigned in GA4?
Your source and medium did not match any of GA4's channel rules. Mediums such as media or paidsearch match nothing. Check the channel preview in the builder above before launching.
Do UTM parameters affect SEO?
Normally no. UTMs are for tracking, but they can create duplicate URL variants. Canonical tags should handle this on your site.
Should I use UTMs on internal links?
No. Internal UTMs can overwrite original attribution, restart the session and reduce reporting accuracy.
Should I use UTMs for organic social posts?
Yes, if you want campaign-level clarity. Use medium=social and consistent source values per platform.
Can I use UTMs for email campaigns?
Yes. Use source=email or newsletter and medium=email, then separate email placements with utm_content.
Do UTMs work with Google Ads auto-tagging?
They coexist, but for Google Ads traffic the gclid takes precedence in GA4. Keep auto-tagging on for Google Ads and use manual UTMs everywhere else.
What is utm_id for?
utm_id carries a campaign ID. GA4's cost-data import matches on utm_id plus utm_campaign, so it is how you get ad spend to sit beside sessions in your reports.
Can other people see my UTM parameters?
Yes. They sit in the address bar, so anyone who receives the link can read your campaign names, and competitors do exactly that. Never put budgets, client names or internal codes in a UTM.
How do I see UTM data in Google Analytics 4?
Open Reports, then Acquisition, then Traffic acquisition. Add Session source/medium and Session campaign columns. Use Explorations for custom drilldowns.
What happens with inconsistent naming conventions?
You get split datasets and unreliable attribution. A standard naming convention is required for trustworthy reporting.
Is this UTM builder free?
Yes. Building single links is free with no signup and no monthly limit. An email unlocks bulk building, CSV export and the ad-platform templates.
Generating UTMs is step one. Is your GA4 actually set up to read them?
Most teams tag links but never finish attribution setup. iExcel will review your tracking and send a clear fix plan. Typical response time: within 48 hours.