UTM Builder

utm_source is where the traffic came from (newsletter, twitter, partner-site). utm_medium is the channel type (email, social, cpc). utm_campaign names the initiative.

utm_term and utm_content are optional — term for paid keywords, content for distinguishing two links in the same email.

Keep them lowercase and consistent. Analytics tools treat Newsletter and newsletter as different sources, which quietly splits your reporting in half.

UTM parameters are key-value pairs added to the end of a link, after a question mark, that tell your analytics tool where a visit came from. The page itself ignores them; Google Analytics, Matomo, HubSpot and most other tools read them when the page loads and file the visit under the source, medium and campaign you wrote.

The builder above takes a destination URL and six fields and assembles the link for you. Paste a link that already has UTMs and the fields fill in from it, so you can change one value without losing the rest. It uses the browser's own URL parser, so a link that already has a query string (?ref=abc) gets the UTMs appended with an ampersand instead of a second question mark, which is the most common way hand-typed UTMs break.

Say you are sending a newsletter on 6 October 2026 that links to a webinar sign-up page at https://example.com/webinar, and the email has two links to it: a button at the top and a text link at the bottom. You want to know which one people click.

Enter the page as the destination URL, newsletter as the source, email as the medium, and webinar-oct-2026 as the campaign. Build the link twice, once with header-button in the content field and once with footer-link. The first result is https://example.com/webinar?utm_source=newsletter&utm_medium=email&utm_campaign=webinar-oct-2026&utm_content=header-button.

Illustration: if GA4 later shows 120 sessions for header-button and 30 for footer-link, the top button drove 120 ÷ 150 = 80% of the tagged newsletter traffic to that page. Without utm_content the two links would be one row and you would never know.

GA4 sorts every session into a default channel (Email, Organic Social, Paid Search and so on) using fixed rules on source and medium. The rules cannot be edited, and a medium that matches none of them sends the traffic to Unassigned, which is where most tagging mistakes end up.

The table below uses the rules from Google's channel definitions page. The pattern for paid channels is the regex ^(.*cp.*|ppc|retargeting|paid.*)$, so cpc, cpm, ppc and anything starting with paid all count as paid. Social and search channels also depend on the source matching Google's list of known social or search sites, so write the source as the site name (facebook, linkedin, google), not as social.

Partly, and the difference catches people. Google states that channel definitions are not case sensitive, so utm_medium=Email still lands in the Email channel. But the values themselves are stored as you typed them, so Newsletter and newsletter show up as two rows in the source report and your totals are split between them.

The fix is a convention, written down: lowercase everything, use hyphens instead of spaces, and keep a shared sheet of approved sources and mediums. If you type a space into the builder, it is encoded as a plus sign in the link; hyphens are easier to read and to filter on.

Most tagging problems are not visible until someone opens a report weeks later. These are the ones to check before a campaign goes out.

A UTM on a link from your own homepage to your own pricing page tells analytics that the visit came from a campaign, which replaces the real source (a Google search, say) for whatever that visitor does next. Use UTMs only on links that point to your site from somewhere else. For internal clicks, use event tracking.

utm_source=social&utm_medium=facebook reads naturally but matches none of GA4's rules: facebook is not a medium, and social is not on the list of social sites. The session goes to Unassigned. Source is the site, medium is the channel type.

newsletter, blast, mailer and e-blast are all reasonable words, and only email-style values (email, e-mail, e_mail, e mail) put traffic in the Email channel. Keep invented detail in utm_campaign or utm_content, where it cannot break channel grouping.

A redirect that drops the query string, a link shortener set up without forwarding, or a form in a plain iframe can all strip UTMs before anything records them. Click the finished link once and check that the parameters are still in the address bar of the page that loads.

Skip them on internal links (see above), on Google Ads when auto-tagging is on (the auto-tagged values take precedence anyway), and on links in organic search results you do not control. Also skip them on links to tools that cannot read them: Google Forms, for example, does not let you add a Google Analytics tag and does not store URL parameters with responses, so a UTM on a Google Form link is recorded nowhere unless you build a pre-filled link into a question instead.

Analytics tells you which campaign brought a visitor. It does not tell you which campaign brought a specific lead, sign-up or order. To get that, the form has to save the UTM values with each response, and the standard way is hidden fields: form fields the respondent never sees, filled from the URL.

In Zunoform, declare the names under Settings → Hidden fields (utm_source, utm_medium, utm_campaign and so on). Any declared name present in the form link is saved with the response and appears in the response view and CSV export. It also goes out with deliveries: webhooks and Zapier catch hooks get a hidden object in the payload, Google Sheets and Excel get one column per hidden field, and Airtable fills same-named columns. HubSpot and Mailchimp do not receive hidden fields, so route CRM attribution through Zapier or a webhook.

If the form is embedded with Zunoform's embed script, the host page's query string is forwarded into the form automatically; a plain iframe snippet forwards nothing. Our full walkthrough, including how to keep UTMs when visitors browse several pages before the form, is in the guide to UTM tracking in forms.