UTM parameters guide: how to name, use and read them in GA4

What are UTM parameters, and what does each one do?

UTM stands for Urchin Tracking Module, a name inherited from Urchin, the web analytics software that Google acquired and developed into Google Analytics. In practice, a UTM parameter is a short piece of text added to a page address after a question mark. The page looks identical to the visitor, but Analytics reads the tag and stores it with the session.

Without tags, part of your traffic lands in reports as “direct” or “referral”, even though it came from a newsletter, an ad or a message sent on WhatsApp. With tags, you can answer the question every business owner asks: where do customers come from, and which campaign deserves next month’s budget?

A full example looks like this: https://example.com/offer?utm_source=facebook&utm_medium=paid_social&utm_campaign=2026-10-autumn-lead&utm_content=video-15s-a. Each pair is joined to the next with an ampersand. If the address already carries parameters of its own, the UTM tags are added with an ampersand too, not with a second question mark.

How to build a UTM link, step by step

The process is short, but the order matters. Most errors happen because someone improvises a link on the spot, with a name they will not remember a month later.

1. Pick the exact destination page: the final address, using https and without needless redirects, because some redirects drop parameters.
2. Set the source: the name of the platform or list, in lower case (facebook, google, newsletter).
3. Set the medium from the list your team has approved, not from inspiration: cpc, email, paid_social, social, referral.
4. Name the campaign using the agreed pattern (date, theme, goal), with no spaces and no accented characters.
5. Add utm_content only if you run several ad variants or place several links in one message and want to compare them.
6. Test the link in a browser, then open the real-time report in GA4 and check that source and campaign appear as you typed them.
7. Record the link in your campaign register (see below), so that nobody has to rebuild it from memory.

For steps 2 to 5 you can use our UTM builder and QR code tool, which also creates the QR code for printed material and helps you keep names consistent from one campaign to the next.

Naming conventions that survive a year of campaigns

GA4 treats upper and lower case as different values: “Facebook”, “facebook” and “FaceBook” show up as three separate sources. The same goes for “paid-social” versus “paid_social”. If two people on the team use different spellings, your report fills up with several rows that should be one.

The rules below are simple and cover nearly every situation:

• Lower case only. There is no reason to mix cases.
• No spaces, no accents, no special characters. A space turns into %20 in the address, and odd characters are hard to read in reports.
• One separator. Choose the hyphen or the underscore and stick to it everywhere.
• A closed list for source and medium. New values are added only after someone approves them, not on the fly.
• Campaign names start with the date as year-month. They then sort chronologically: 2026-10-autumn-lead, 2026-11-black-friday.
• Descriptive names, not secret codes. A new colleague should understand “2026-10-autumn-lead” without asking.

The utm_medium value deserves special care, because GA4 uses it to group traffic automatically into channels such as Email, Paid Search and Paid Social. Paid search ads are usually tagged “cpc” and email messages “email”. An invented medium, such as “promo” or “ad1”, often ends up in “Unassigned” or “Referral”. Exactly how values map to channels depends on Google’s current rules, so check the official documentation at support.google.com/analytics.

Where to use UTM tags, and where not to

Not every link needs tags. The practical rule: put them on links you control that lead to your website from outside it.

Places where UTM tags help

• newsletters and automated emails (each button can carry its own utm_content);
• Facebook and Instagram ads, where you can fill in the URL parameters field for each ad;
• organic social posts that send people to your site, especially the link in your bio;
• partnerships, press releases, sponsored articles and creator collaborations;
• printed material with a QR code, where otherwise you would only see “direct”;
• email signatures and messages sent through WhatsApp or Messenger, when you want to measure a specific action.

Places where UTM tags do damage

Never put UTM tags on internal links on your own site, for example from a banner on the homepage to a product page. When a visitor clicks such a link, GA4 can replace the real source with your internal label. To measure banner clicks, use events, not UTM tags.

For Google Ads, auto-tagging normally does the job: it adds a click identifier and passes campaign data into Analytics when the accounts are linked. If you add manual tags on top, the two systems can overlap, and the outcome depends on your account settings. Check this setting in the current interface before you add UTM tags to Google Ads links.

How to fill in UTM tags in Facebook and Instagram Ads

In Meta ads, the parameters go into a dedicated field on the ad, and the platform offers dynamic parameters that are replaced automatically with the name of the campaign, ad set or ad. You do not type each variant by hand, and the names in Analytics stay aligned with those in the ad account. Our Facebook and Instagram ads service usually relies on this approach.

A typical template: utm_source=facebook, utm_medium=paid_social, utm_campaign holding the campaign name, utm_content holding the ad name. One detail to watch: if you rename a campaign after launch, the label in links that are already live can change, and your history in Analytics splits in two. Choose names carefully at the start, and for serious analysis keep a numeric campaign ID in a lookup table.

The exact fields and macro names change from time to time, so confirm them in Ads Manager. As a principle, stable campaign names are safer than long texts full of special characters.

How to read UTM results in GA4

Tagged sessions appear in the traffic acquisition report, broken down by session source/medium or by session campaign. There you see how many sessions each tag brought, how long visitors stayed and how many key events (conversions) they generated. You can add a secondary dimension, such as ad content, to compare variants.

The reading order we recommend:

1. Start with the medium, to see how much comes from paid, email, social and organic search.
2. Go down to the campaign and compare not only traffic but conversions and the cost shown in the ad platform.
3. Only then look at ad content to pick the winning variant.
4. Check the rows labelled “(not set)”, “(direct) / (none)” and any duplicate variants: they show where tags are missing or were spelled differently.

One thing to remember: UTM tags show where the session came from, not who actually bought. A customer may see an ad on a phone, return a week later from a newsletter and buy then. The attribution models in GA4 treat that story differently, so do not expect GA4 figures to match Ads Manager exactly. For measurement setup, see our guide to conversion tracking with GA4 and the Meta Pixel, and for reporting in plain language, GA4 for business owners.

Common UTM mistakes

• Mixed upper and lower case. The result: the same source appears three times in the report.
• UTM tags on internal links. They overwrite the real source and distort attribution.
• An invented medium. Traffic no longer lands in the right channel and ends up in “Unassigned”.
• Personal data in tags. Never put email addresses, names or phone numbers in parameters. The full address appears in browser history, server logs and reports, so keeping it clean also helps with GDPR compliance.
• Shortened links that are never tested. A link shortener can drop or alter parameters. Test the final link.
• No documentation. After six months, nobody knows what “camp_v2_final” means.
• Tags on everything, with no purpose. If you will never analyse utm_term or utm_content, do not fill them in. Complexity is paid for in mistakes.

On-site tracking often depends on user consent. This text is informative and is not legal advice. For cookie and measurement settings, confirm the current requirements with a lawyer or your data protection officer.

UTM governance: how teams and agencies avoid chaos

When several people work on campaigns (in-house marketing, an agency, freelancers), a guide in a document nobody opens is not enough. You need a few small but mandatory elements.

The first is a campaign register: a shared spreadsheet with columns for launch date, channel, final link, owner and status (planned, live, ended). Every new UTM link goes in before it is used. The second is a list of allowed values for source and medium, on a separate tab, with data validation in the spreadsheet so that nobody can type “Facebook” instead of “facebook”.

The third is an owner. This does not need a new job; it needs one person who approves new values and checks the monthly report for duplicates. The fourth is a rule for agencies: the contract or brief states that all links are built to your convention, and the register stays yours, not the supplier’s. When you change agencies, the history stays with you.

If you already have years of mixed data, do not try to repair it retroactively. Fix the convention from now on, note the change date in an annotation, and compare periods with care.

How we work with UTM tags

For clients whose campaigns we run, the naming convention is agreed before the first ad, in the same meeting where we choose the goals and the conversion events. We keep the register in a shared spreadsheet that the client can see too, and at the end of each month we search GA4 for values that break the list.

We do not treat UTM tags as an end in themselves: they matter only if they lead to decisions, and decisions depend on end-to-end measurement, from event to report. If you want to check how measurement stands on your own site, see our conversion rate optimisation service, where tracking setup is the first step. For a review of your measurement, you can also write to us directly.

In short

• The three mandatory tags are source, medium and campaign; the rest are optional.
• Write everything in lower case, with no spaces or accents, using the same separator throughout.
• Do not put UTM tags on internal links, and do not layer manual tags over Google Ads auto-tagging without checking your settings.
• Keep personal data out of parameters.
• Keep a campaign register and a list of allowed values, with one owner.
• Check monthly for duplicate rows, “(not set)” and “(direct) / (none)”.