Guide · Analytics
UTM Parameters: How to Tag Links for Clean Reports
UTM parameters are short tags you add to the end of a link so Google Analytics can tell where a visit came from. Tag every link you control, use lowercase values, and follow one naming rule. That keeps your reports clean. This guide covers the tags, a naming rule and the mistakes that split reports.
What UTM parameters are
A UTM parameter is a labelled piece of text at the end of a web address. When someone clicks the link, Google Analytics reads the labels and files the visit under the campaign you named. The labels all start with
utm_.Google says that when a user clicks a tagged link, the values are sent to Analytics. In Google Analytics 4 (GA4) you can then see them in the Traffic acquisition report, under Session source, Session medium and Session campaign.
Without tags, an email click or a social post often lands in a vague bucket. With tags, you can say which newsletter, which post or which partner sent the visit.
Sources: Google Analytics Help, [GA4] URL builders: Collect campaign data with custom URLs
The UTM tags GA4 reads
Google lists these parameters for GA4. The first three do most of the work.
Tag What it names Example utm_source The referrer, such as a newsletter or a site newsletter4 utm_medium The marketing medium email utm_campaign The product, slogan or promo code spring_sale utm_id A campaign ID, used for GA4 data import a number or short code utm_term The paid keyword your keyword utm_content Tells apart creatives or links in one message toplink Google also lists utm_source_platform, utm_creative_format and utm_marketing_tactic. Its help page says the last two are not currently reported in GA4 properties, so most teams can skip them.
Here is a full link:
https://www.example.com/?utm_source=newsletter1&utm_medium=email&utm_campaign=spring-sale. A question mark starts the tags. An equals sign joins each tag to its value. An ampersand separates the pairs.For GA4, Google says you need at least one utm parameter. In the older Universal Analytics, you needed at least utm_source and utm_medium. Using source, medium and campaign together is still the safest habit, and Google says you should always use those three.
Sources: Google Analytics Help, [GA4] URL builders: Collect campaign data with custom URLs; Google Analytics Help, [UA] Collect campaign data with custom URLs
A simple naming rule
Reports only stay clean if everyone names things the same way. Google gives one hard fact to build on: parameter values are case sensitive. It says
utm_source=googleis different fromutm_source=Google.So one person writes "Email" and another writes "email", and your report shows two rows for one thing. A rule fixes this. Our suggested rule has four parts:
- Use lowercase letters only.
- Use a hyphen or an underscore instead of spaces, and pick one of them for the whole team.
- Choose medium names from a short list, such as email, cpc, social and referral, and do not invent new ones.
- Write campaign names in the same order each time, for example topic then month, like spring-sale-2025-03.
Keep the rule in a shared sheet. Add a new row for each link. Anyone who builds a link checks the sheet first.
Google offers a Campaign URL Builder for links to websites. It adds the tags for you, but it does not enforce your naming rule, so the sheet still matters.
Sources: Google Analytics Help, [GA4] URL builders: Collect campaign data with custom URLs
Mistakes that split your reports
Most messy reports come from a handful of habits. Check your own links against this list.
Mistake What it does to the report Fix Mixed capital letters Splits one source into two rows Lowercase everything Two names for one medium, such as "email" and "e-mail" Splits one medium into two rows Keep a short medium list Spaces in values Can make links messy or broken when pasted Use hyphens or underscores Missing utm_medium or utm_source Leaves visits with thin or vague labels Always set source, medium and campaign Tagging every link on your own site Our editors advise against it: it can muddy where a visit really started Tag links that bring people in from outside Reusing one campaign name for different pushes Blends results you want to compare Give each push its own name The advice on internal links is our editors' view, not a Google rule. The case rule and the source and medium points come from Google's help pages.
Sources: Google Analytics Help, [GA4] URL builders: Collect campaign data with custom URLs; Google Analytics Help, [UA] Collect campaign data with custom URLs
UTM tags and Google Ads auto-tagging
If you run Google Ads, you meet a second kind of tag. Auto-tagging adds a parameter called GCLID, short for Google Click Identifier, to the link people click. Google says it is turned on by default for new accounts.
Google also says that in GA4, auto-tagging is prioritised over manual tagging because there is no override option. Its help page says you can still tag ad links by hand with UTM parameters if you want to keep tracking Google Ads that way.
The practical point is simple. Use UTM parameters for email, social, partners and other non-Google-Ads links. For Google Ads, check how auto-tagging is set before you add your own tags.
One more check from Google: a small share of sites serve an error page when a link carries extra parameters. Click one of your tagged links before a launch and make sure the page loads.
Sources: Google Ads Help, About auto-tagging; Google Analytics Help, [GA4] URL builders: Collect campaign data with custom URLs
A five step check before you launch
Run this short list each time you send a tagged link.
- Open the naming sheet and copy the exact source, medium and campaign names.
- Build the link with the Campaign URL Builder or by hand.
- Check that every value is lowercase and has no spaces.
- Click the link and confirm the page loads.
- After a day, open the Traffic acquisition report and look for your campaign name. If it appears as two rows, fix the sheet.
Note that Google says UTM information is not captured in the Landing page + query string or Page path + query string dimensions. It appears in the Page location dimension instead. Look there if you want the full tagged address.
Sources: Google Analytics Help, [GA4] URL builders: Collect campaign data with custom URLs
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