UTM parameters are tags at the end of a URL that tell analytics where a visit came from.

UTM stands for Urchin Tracking Module. Urchin was a web analytics company that Google bought in 2005, and its tags became the standard for campaign tracking in Google Analytics and many other tools.

There are five standard parameters. utm_source names the site or app, utm_medium the kind of channel (such as social or email), utm_campaign the campaign, utm_term the paid keyword, and utm_content the link or version.

UTM tags do not change the page a visitor sees. They only label the visit, so the destination site's analytics can group visits by source and campaign.