Definition
What is UTM Parameters?
UTM parameters are tags appended to a URL (such as utm_source, utm_medium, and utm_campaign) that tell analytics tools where a click came from. When a user follows a UTM-tagged link, GA4 reads the parameters to attribute the session to the correct source, medium, and campaign. They are the standard way to track links in email, ads, and social posts.
Why it matters
Consistent UTM tagging is what makes campaign performance measurable, because untagged links collapse into Direct or Referral and lose their campaign context.