UTM Link Builder

UTM parameters are five fields appended to a URL that tell an analytics tool where a visit came from. Nothing reads them but your own analytics: they change no behaviour, affect no ranking, and are ignored by every crawler.

A campaign URL builder is therefore a formatter and nothing more. The tracking is already there — GA4 records the parameters whatever they say — so the only thing a builder can do for you is stop you writing a value that will be reported as two.

Three of the five actually matter. utm_source, utm_medium and utm_campaign are what GA4 reports on. Leave any of them out and the visit lands in "unassigned", which is the row nobody can act on. Term and content are for splitting a campaign further, and most campaigns never need them.

Capitals are the expensive mistake. GA4 matches these as literal strings, so Facebook and facebook are two different sources. One campaign arrives split across two rows in every report you run afterwards — and it cannot be fixed later, because the value is written onto the hit as it arrives. Lowercase everything, always.

Medium is a category, not a name. It answers "how did they get here" — email, cpc, social, referral — and it is the field that groups campaigns together in a report. Source answers "from where": the specific newsletter, the specific site. Swapping the two is the second most common mistake after capitals, and it makes every grouping in the report meaningless.

Never tag an internal link. A visitor moving between your own pages through a UTM link starts a new session attributed to that campaign. The campaign gets credited with traffic it did not bring, and the original source that did bring it disappears.

The fragment stays last. Parameters go before #section, never after. Anything after the hash is never sent to the server and never reaches analytics, so a link built the other way round silently tracks nothing.

These links are public. Whatever you put in a campaign name is visible in the address bar, in shared links, and in referrer headers on the next site the person visits. It is not the place for internal codenames or client names.