UTM Parameters

When you click on a link, you see an address at the top of your browser. Sometimes there’s a long appendage attached to this address with a question mark and words like “utm_source=newsletter”. These are UTM parameters: optional additional details that the sender of the link has attached themselves. They don’t change anything about the page you get to see. They only tell the operator of the page where you’re coming from. The abbreviation comes from “Urchin Tracking Module”, named after an analytics software that Google bought in 2005.

Why companies want to know where a click comes from

A company advertises a product simultaneously across multiple channels: via email, on Instagram, through paid ads, and in a podcast. At the end of the month, it sees 50,000 visitors on the website. Without tagging the links, nobody knows which channel delivered these visitors. That also means you don’t know which advertising budget you can cut and which one you should double.

This is exactly the gap that UTM parameters close. Each channel gets its own tagged link. Afterward, the analysis reveals: 12,000 visitors from the newsletter, 3,000 from Instagram, 800 from the podcast. Because this can be translated directly into money, UTM parameters are a standard tool in almost every marketing department.

It’s important to distinguish this from cookies. A cookie is a small file that a website stores on your device to recognize you later. UTM parameters don’t store anything on your device; they only exist within the link. That’s why they’re considered a comparatively harmless method and still work even when browsers block third-party cookies.

The five fields in the link

A UTM link consists of the normal address, a question mark, and after that any number of pairs of name and value. The pairs are joined with an ampersand. An example: exampleshop.com/shoes?utm_source=instagram&utm_medium=social&utm_campaign=summer2025. The server simply delivers the “shoes” page and writes the appendage into its statistics.

Five fields are common. “utm_source” names the specific source, such as instagram or newsletter. “utm_medium” names the type of channel, such as social, email, or cpc for paid clicks. “utm_campaign” names the campaign the link belongs to. In addition, there’s “utm_content”, used to distinguish two variants of the same advertising banner, and “utm_term” for search terms.

Anyone can choose the values freely, and that’s the biggest source of error. If one colleague writes “Newsletter” and her colleague writes “newsletter”, the analytics program counts these as two separate channels. Large companies therefore establish fixed naming lists. A second typical misconception: UTM parameters don’t identify individuals. They only describe the path of a click, not the person behind it.

The long link in the newsletter

You encounter UTM parameters daily, usually without noticing. They’re embedded in links from promotional emails, under YouTube videos, in banners, and in influencer posts. If an address in the browser bar is suddenly three times longer than expected, advertising tracking is often behind it. You can usually simply delete the part after the question mark, and the page still loads.

In the reporting language of the tech industry, UTM parameters come up wherever customer acquisition is discussed. Analytics services like Google Analytics, Matomo, or Plausible build their channel reports on this basis. The term also comes up regularly in debates about data privacy and the end of third-party cookies, because UTM parameters are considered a more robust alternative.

New AI tools are now also getting involved. When a chatbot links to sources or a company optimizes its content for answer engines, it wants to measure how many visitors result from that. Marketing teams create their own UTM sources for this purpose. The ancient link appendage from 2005 thus becomes a measurement instrument for a very new channel.