UTM builder: see which posts bring you clients

01What is a UTM link, and why bother?

A UTM link is a normal link with a few tags added after a question mark. For example, yoursite.com/guide?utm_source=instagram&utm_medium=social&utm_campaign=free-guide. The page looks the same to the visitor. The only difference is that your analytics now knows the visit came from Instagram, as part of your free guide campaign.

Without tags, a lot of your traffic lands in a vague bucket. Clicks from Instagram stories, email apps, PDFs and podcast apps often show up as "direct" or a generic referral, so you cannot tell your newsletter from your bio link. With tags, you can.

That matters because effort is not evenly spread. When coaches tag their links properly for a month or two, they usually find one or two channels bring most of the enquiries, and some of the content that takes the most time brings almost nothing. You cannot see that without the tags.

02What do source, medium, campaign, term and content mean?

Each tag answers one question. Keep them separate and your reports stay readable.

Two naming rules do most of the work. Use lowercase only, and use hyphens instead of spaces. Spaces turn into %20 in the link and are easy to type slightly differently next time. Write your choices down once, then reuse them. The saved links list above helps with that.

03Which utm_medium values does GA4 recognise?

GA4 sorts visits into channels like Email, Organic Social and Paid Search using rules based on your source and medium. If your medium does not match a rule, the visit can end up as "Unassigned", which is no use to anyone. These are the values from Google's own default channel group rules, simplified:

The presets in our UTM builder follow these rules, so a newsletter link lands in Email and a podcast link lands in Audio without you having to remember any of it.

04Should you use UTM tags on internal links?

No. This is the most common mistake we see. If you tag a banner on your own homepage with utm_source=homepage, every visitor who clicks it starts a new session in GA4 with "homepage" as the source. The real source, the Instagram post or email that brought them in, is overwritten. Your reports then say your homepage is your best marketing channel.

Tag links that point to your site from somewhere else: social profiles, posts, emails, ads, podcast notes, partner sites and PDFs. For clicks inside your own site, use GA4 events or the page path reports instead. Our builder warns you if your source looks like part of your own site.

05How do you see UTM results in GA4?

In GA4, go to Reports, then Acquisition, then Traffic acquisition. Change the main column to "Session source / medium" or "Session campaign". Each tagged link now shows as its own row, with visits, engaged sessions and any key events you have set up, such as form fills or bookings.

Visits are only half the answer. What you want to know is which links lead to enquiries and clients. Set up a key event for your booking or opt-in form, then compare channels on that, not on clicks. A channel that sends 40 visits and 3 calls beats one that sends 400 visits and none. If you want to see which step after the click loses the most people, our funnel leak calculator shows it in a couple of minutes.

06How this builder works

The builder works in four steps, all inside your browser.

1. It reads your URL. If you left out https:// it adds it and tells you. Any parameters already on the link are kept, except old UTM tags, which are removed so the link is not tagged twice. A #section stays at the end, after the tags, which is where analytics expects it.
2. It tidies the values. With "Tidy values for me" on, every value is made lowercase, spaces become hyphens and double hyphens are collapsed. So "Black Friday Launch" becomes black-friday-launch.
3. It encodes and joins the tags. Each value is URL encoded, so characters like & or ? cannot break the link.
4. It predicts the GA4 channel. From your source and medium it applies a simplified version of GA4's default channel rules. Email in either field means Email. A medium such as cpc or ppc with a search, social or video source means Paid Search, Paid Social or Paid Video. A medium of social, or a social source without a paid medium, means Organic Social. If nothing matches, it warns you the visit may land in Unassigned.

It then checks for nine mistakes: a missing https://, an http:// link, old UTM tags, a #section, spaces, capitals, a value that clashes with a link you saved earlier, a tag on what looks like an internal link, and a source that is the same as the medium. It also flags links over 2,000 characters, which some apps cut short.

07Ways the result can mislead you

A tagged link can still give you wrong numbers. These are the ways it usually happens.

1. Capitals split your reports. GA4 treats Instagram and instagram as two different sources. One person on your team typing it differently is enough to split a month of data in two. Keep tidy on, and reuse saved links.
2. Tags on internal links wipe out the real source. If someone arrives from Google and then clicks a tagged link on your own site, GA4 can credit the visit to your tag instead of Google. Only tag links that point to your site from somewhere else.
3. An unrecognised medium lands in Unassigned. Mediums like "bio" or "ig" mean nothing to GA4's channel rules. Use social, email, cpc, video, audio, referral or affiliate.
4. Redirects can drop the tags. Some link shorteners, tracking tools and site redirects strip the query string. Click your finished link once and check the address bar on the landing page still shows the tags.
5. Cookie banners hide visits. In the UK and EU, GA4 only records full data from people who accept analytics cookies. Your tagged link may get more clicks than GA4 shows, so compare trends, not exact counts.

08What it will not tell you

This is a link builder. It does not do the following.

• It does not check that the landing page loads, or that GA4 is installed on it.
• It does not count clicks. GA4 does that once a visitor lands on your site.
• It does not shorten links.
• Its channel prediction is a simplified version of GA4's rules, not GA4 itself. GA4 has the final say.
• Saved links stay in this browser. Clear your browser data, or open another device, and they are gone, so export the CSV if you need a record.

If the links are tagged but you still cannot see which posts bring in clients, the gap is usually further down: the page, the follow-up or the tracking setup. Our funnel leak calculator shows which step is losing the most.

09Common questions

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