UTM parameters
Five query parameters that label a destination address so the analytics tool on that site can group traffic by campaign.
Updated August 14, 2026
UTM parameters are five labels appended to a destination address: utm_source, utm_medium, utm_campaign, utm_term and utm_content. They carry no behaviour. They are read by the analytics tool running on the destination site, which groups sessions by them — the redirect service only makes sure they survive the journey and arrive intact.
On a short link they are filled in once and appended to whichever destination is finally chosen, whether that is the main address, a targeting rule or a split variant, with any parameters the destination already had left untouched. That is what stops a targeted link from losing its campaign tagging on the way.
Their weakness is that they are free text, and free text drifts. Facebook, facebook and FB are three separate rows in every report that reads them, and a rename halfway through a quarter splits one campaign in two. Agree on lower case and a fixed vocabulary for source and medium, keep the builder as the single way links are made, and never put anything personal in utm_term — these values end up in logs and shared reports.