01
What UTM parameters do
UTM parameters are tags at the end of a link, like ?utm_source=instagram&utm_medium=social&utm_campaign=spring-sale. When someone clicks, your analytics tool reads them and records where the visit came from, so you can tell your Instagram bio link from your TikTok profile link and your newsletter.
Google Analytics 4 asks you to always set three of them: utm_source (where: instagram), utm_medium (what kind of traffic: social) and utm_campaign (why: spring-sale). utm_content is useful on social to tell apart links in the same campaign, such as a bio link and a story link.
02
Get the channel right
GA4 sorts traffic into channels using these tags. A visit counts as Organic Social when the source is a known social site or the medium is social (or social-network, social-media, sm). It counts as Paid Social when a social source has a paid medium, such as cpc, ppc or anything starting with paid. Email needs email as the source or medium.
If you invent a medium like "bio" or "post", GA4 may put the visits in Unassigned, where they're easy to miss. The builder shows the channel the link will most likely land in.
03
Keep the names consistent
Values are case sensitive: GA4 reports utm_source=Instagram and utm_source=instagram as two different sources. That's why the builder lowercases by default and turns spaces into dashes. Agree on a short list of names and reuse it, the same campaign name on every platform makes the report readable.
Sources and methodology
Numbers checked on October 17, 2026.
Parameter names and their roles come from Google Analytics 4's URL builder documentation; the channel preview follows GA4's default channel group rules for Organic Social, Paid Social and Email. GA4's full list of social sites isn't published, so the social-source check is an approximation. The link is built in your browser.
- URL builders: Collect campaign data with custom URLs — Google Analytics Help, October 17, 2026
- Default channel group — Google Analytics Help, October 17, 2026
