UTM links: what they are, how to build and read them in GA4
What UTM links and the source, medium and campaign parameters are, how to build them, how to read them in Google Analytics 4, ready examples and mistakes.
In 30 seconds
- UTMs are labels added to the end of a link.
- They tell analytics tools where a visit comes from.
- The three you always need: source, medium and campaign, always written the same way and in lowercase (GA4 is case-sensitive).
- In Google Analytics 4 you read them in Traffic acquisition, with the «Session source / medium» and «Session campaign» dimensions.
- Don't use them on internal links or in Google Ads with auto-tagging turned on.
UTM links are ordinary links with labels (UTM parameters) added after the question mark, telling Google Analytics and other analytics tools where a visit comes from: which site or app (source), which type of channel (medium) and which campaign. They don’t change the page that opens: they’re only there for measurement.
You sent a newsletter and published a post: the next day the site has more visits. But how many came from the newsletter and how many from the post? Without UTMs you often can’t tell.
What UTM parameters are
They’re labels added to the end of a link, after the question mark, separated by &. UTM stands for Urchin Tracking Module: Urchin was the web analytics software Google bought in 2005, which became Google Analytics. The name stuck.
An example from the newsletter of Five Leaf, Peacchy’s practice company:
fiveleaf.example/evening-teas?utm_source=newsletter&utm_medium=email&utm_campaign=evening-teas-october
The three labels you always need
| Label | What it says | Example |
|---|---|---|
utm_source |
Who sends the visit | newsletter, instagram |
utm_medium |
The type of channel | email, social, cpc |
utm_campaign |
The campaign name | evening-teas-october |
Then there are optional ones:
| Label | What it says | Example |
|---|---|---|
utm_content |
Which link or creative, if there’s more than one | top-button, bottom-button |
utm_term |
The keyword, in search ads | evening-herbal-tea |
utm_id |
A campaign ID, for importing cost data | 2026-11-teas |
Google Analytics 4 also recognises utm_source_platform, utm_creative_format and utm_marketing_tactic, useful in large ad campaigns.
How to build a UTM link
- Copy the landing page address.
- Choose source, medium and campaign following the team’s rules.
- Write the link by hand or with a builder: you can use Peacchy’s free UTM link builder, which runs in your browser and cleans up spaces and capitals.
- Test the link before using it: it must open the right page.
- If it’s long, shorten it for social media or print, but keep the original in a spreadsheet.
Ready-made examples
| Channel | utm_source | utm_medium | utm_campaign |
|---|---|---|---|
| Newsletter | newsletter | evening-teas-october | |
| Instagram post (link in bio) | social | matcha-launch | |
| Paid Meta ad | paid_social | black-friday-2026 | |
| Creator collaboration | creator-name | influencer | matcha-launch |
| QR code on packaging | packaging | qr | box-2026 |
How to read UTMs in Google Analytics 4
In GA4 go to Reports → Acquisition → Traffic acquisition and choose the Session source / medium or Session campaign dimensions. GA4 also uses the medium to assign the visit to a default channel group: for example email goes into the Email channel, cpc into Paid Search (if the source is a search engine), social into Organic Social. If you invent mediums (“mail”, “social-post”), visits may end up in the Unassigned group.
Rules to avoid confusion
- Always lowercase: GA4 is case-sensitive, so “Newsletter” and “newsletter” become two different sources in reports.
- Hyphens instead of spaces: “evening-teas-october”, not “Evening teas October”.
- Standard mediums: use values like email, social or cpc, which analytics tools recognise when grouping visits by channel.
- Names that make sense: in six months “campaign1” won’t mean anything to anyone.
- One shared spreadsheet with every link created and the team’s rules: the easiest way to avoid three names for the same campaign.
- Never on internal links: they overwrite the visit’s real source.
What UTMs don’t do
UTMs don’t count anything on their own. Visits are measured by the site’s analytics tool, which in Italy (and generally in the EU) must only start after cookie consent when it isn’t anonymous, as required by the Italian data protection authority’s 2021 guidelines. So some visits won’t be counted: that’s normal, and comparisons between campaigns remain valid.
Sources
Which utm_medium do you use in a newsletter link?
Correct! The newsletter arrives by email: the medium tells you the type of channel.
Not quite. Social is a different channel; and "October Newsletter!!" is a badly written campaign name, not a medium.
Frequently asked questions
Do UTMs collect data about people?
No, on their own they're just text in a link. Visits are measured by the site's analytics tool, which must respect cookie consent. Never put data like emails or names in UTMs.
Can I use UTMs on my site's internal links?
No. An internal link with UTMs makes GA4 think the visit came from a new source and overwrites the real one (for example a Google search).
Do UTMs affect SEO?
No. Google ignores UTM parameters for ranking. To be safe, pages have a canonical pointing to the clean address, so UTM versions aren't indexed.
Should I use UTMs in Google Ads?
Usually not: with auto-tagging on, Google Ads adds its own parameter (gclid) and GA4 recognises campaigns and keywords by itself.
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