What is a UTM?
A UTM is a set of query parameters added to the end of a link so that analytics can tell where a click came from. The name comes from the Urchin Tracking Module, the software Google bought in 2005 and turned into Google Analytics. Any analytics tool that reads query strings understands them.
Worked example
One newsletter link, tagged.
| Untagged link | https://example.com/pricing |
|---|---|
| Tagged link | https://example.com/pricing?utm_source=newsletter&utm_medium=email&utm_campaign=august-launch |
| Reported source | newsletter |
| Reported medium | |
| Reported campaign | august-launch |
The click lands in analytics as newsletter / email / august-launch instead of direct traffic Without the tag, an email client that strips the referrer makes that visit indistinguishable from someone typing your URL. The tag is the only thing that survives.
How a UTM actually works
A UTM is not a tracker, a script or a cookie. It is text in the URL. When someone clicks a tagged link, their browser requests your page with those parameters attached, your analytics script reads them off the address bar, and it stores them against that visit.
That mechanical simplicity is why UTMs are worth the effort. There is nothing to install, nothing to consent to, and it works in every analytics tool ever made because it is just a query string. It also survives situations where nothing else does:
- Email clients that strip the referrer header, which is most of them.
- Apps that open links in an in-app browser and pass no referrer.
- Links in PDFs, in QR codes, in a podcast description, on a printed conference banner.
- Traffic from HTTPS sites to your site where the referrer is truncated to the domain.
The catch is that a UTM only exists if a human remembered to add it, and remembered to spell it the same way as last time, which is why UTM data quality is an operations problem far more than a technical one. The free UTM builder removes most of that risk by generating the link for you, lowercased and consistently formatted.
What UTMs look like in a report
Once tagged, campaigns stop hiding inside direct traffic and get their own rows: source, medium and campaign, each countable and each comparable across channels.
The payoff is not the pretty table, it is the arithmetic it enables. Spend on one campaign, count the conversions carrying its tag, and you have a cost per conversion that does not depend on anyone's dashboard.
mrkr keeps the campaign parameters on the session, so a signup or a purchase later in that visit carries the campaign that produced it, which is what makes revenue attribution work without a tag manager.
Live demo
See it on real data. The live demo is a fully populated dashboard on demo traffic, with no signup and no card.
Open the live demoThe rules that keep UTM data usable
Lowercase everything, always
utm_source=Facebook and utm_source=facebook are two different rows in every analytics tool. Case sensitivity splits one campaign into several and there is no way to merge them afterwards.
Hyphens, never spaces
A space becomes %20 and looks like a different campaign depending on how the link was encoded. Pick hyphens, write it down, enforce it.
Never tag internal links
A UTM on a link between two of your own pages starts a new campaign attribution mid-visit and overwrites the real source. This is the single most common way teams destroy their own attribution data.
Never put anything personal in a UTM
UTMs end up in browser history, in referrer headers, in shared links and in logs. An email address or a customer id in a UTM is a data leak with a long tail.
Where UTMs stop working
UTMs answer one question well: which link did this click come from. They are poor at everything else, and it is worth being clear about the limits.
They do not survive a redirect that drops the query string, they are frequently stripped by link shorteners and by some social apps, and they can be edited by anyone, so treat inbound UTM values as untrusted text rather than as facts.
They also say nothing about what happened before the click. If a customer read three blog posts over two weeks and then clicked a newsletter link, the UTM credits the newsletter for all of it. That is a question for an attribution model, not for a tag.
Finally, a UTM on its own does not connect a click to a purchase days later. That needs identity persisting across sessions, which cookieless analytics deliberately does not provide. Within a single visit, campaign to conversion works fine cookielessly.
FAQ
What does UTM stand for?
Urchin Tracking Module. Urchin was a web analytics company Google acquired in 2005, and its parameter format became the standard that every analytics tool now reads.
Do UTM parameters affect SEO?
They can create duplicate URLs if tagged links get indexed, so keep a canonical tag on the clean URL. Never use UTMs on internal links, which is both an SEO risk and a guaranteed way to overwrite your own attribution data.
Do UTMs require cookie consent?
Reading a UTM from the URL stores nothing on the visitor's device, so it does not itself trigger the ePrivacy consent requirement. What needs consent is whatever your analytics stores afterwards. In mrkr's default cookieless mode nothing is stored, so campaign reporting works without a banner.
Start with one line of HTML.Your first visitors show up within a minute.