UTM? What’s That?

October 26, 2026

Ever clicked a link from ChatGPT, Claude, or a newsletter and noticed some extra text at the end of the URL? Here's what it means.

I was browsing the web recently and noticed something interesting.

Sometimes, when I click a link from ChatGPT or another platform, the URL contains something like this:

?utm_source=chatgpt.com

You've probably seen something similar when clicking links from newsletters, social media, or advertisements.

At first glance, it looks like random text added to a URL. But there's actually a reason it's there.

It's called a UTM parameter, and it's one of the ways websites understand where their visitors are coming from.

Let's talk about how it works.

So, What Exactly Is UTM?

UTM stands for Urchin Tracking Module.

The name comes from Urchin, a web analytics company whose technology became part of what we now know as Google Analytics.

UTM parameters are pieces of information added to a URL to help identify the source of website traffic.

Let's say I share an article from my blog:

https://idoevergreen.me/blog

Now, imagine I share that same article on LinkedIn, but I want to know how many visitors came specifically from that post.

I could add some UTM parameters:

https://idoevergreen.me/blog?utm_source=linkedin&utm_medium=social&utm_campaign=blog_promotion

It's still the same page.

The difference is that the second URL tells an analytics system a little more about how the visitor arrived.

In this case:

  • utm_source=linkedin tells us where the visitor came from.
  • utm_medium=social identifies the type of channel.
  • utm_campaign=blog_promotion identifies the campaign.

If my website has analytics configured to collect these parameters, I can use them to understand how my LinkedIn promotion is performing.

Pretty useful, right?

The Five Common UTM Parameters

There are five UTM parameters you'll commonly encounter.

1. utm_source

This identifies the source of the traffic.

For example:

utm_source=google
utm_source=linkedin
utm_source=chatgpt.com

2. utm_medium

This identifies the marketing or referral channel.

utm_medium=email
utm_medium=social
utm_medium=cpc

Here, cpc means cost per click, commonly used for paid advertising.

3. utm_campaign

This identifies a particular marketing campaign or promotion.

utm_campaign=product_launch

4. utm_content

This helps distinguish between multiple links or variations within the same campaign.

For example, you might have two buttons in an email and want to know which one people click more often.

utm_content=header_button
utm_content=footer_button

5. utm_term

This is commonly used to identify paid-search keywords.

utm_term=javascript_tutorial

There are additional parameters, including utm_id and utm_source_platform, but these five are a good starting point.

This is actually what got me interested in the topic.

When ChatGPT shares links to websites, some of those links include a parameter like:

utm_source=chatgpt.com

The purpose is to help the destination website identify traffic arriving through ChatGPT.

Think about it.

Traditionally, website owners paid attention to traffic coming from search engines like Google or Bing.

But now, people are also discovering websites through AI assistants.

Someone might ask ChatGPT:

What are some good resources for learning React performance optimization?

ChatGPT might recommend an article from a developer's blog.

When the person clicks that link, the blog owner may be able to identify ChatGPT as the source of that visit.

This creates another way for publishers and developers to understand how people discover their content.

However, not every AI assistant or every link uses the same tagging convention. Some visits are identified through HTTP referrer information, and others may appear as direct traffic.

Also, a UTM parameter isn't proof that a visit genuinely came from a particular platform. Anyone can manually create a URL containing utm_source=chatgpt.com.

How Does UTM Tracking Actually Work?

Here's where things get a little more technical.

A URL can contain a query string, which starts with a question mark (?).

For example:

https://example.com?utm_source=linkedin

The query string contains key-value pairs.

If you have multiple parameters, they're separated using an ampersand (&).

https://example.com?utm_source=linkedin&utm_medium=social

When someone opens that URL, the browser requests the page using the URL, including its query string.

The website can then access those parameters.

For example, in JavaScript:

const params = new URLSearchParams(
  window.location.search
);

const source = params.get("utm_source");

console.log(source);
// "linkedin"

That's it.

The browser gives us access to the query string, and URLSearchParams makes it easy to read individual parameters.

Of course, reading the value isn't the same as tracking it.

For tracking, you need to send the relevant information to an analytics system or store it somewhere.

Tools like Google Analytics can collect campaign information from tagged URLs when properly configured.

Absolutely.

You don't need a special service to create UTM parameters.

Let's say I'm promoting a new episode of my podcast on three platforms.

I could create these links:

LinkedIn

https://podcast.idoevergreen.me?utm_source=linkedin&utm_medium=social&utm_campaign=new_episode

Instagram

https://podcast.idoevergreen.me?utm_source=instagram&utm_medium=social&utm_campaign=new_episode

Newsletter

https://podcast.idoevergreen.me?utm_source=newsletter&utm_medium=email&utm_campaign=new_episode

All three links lead to the same website.

But if my analytics setup captures those parameters, I can compare how the different channels perform.

I could answer questions like:

Which platform sends the most visitors?

Which campaign gets the most engagement?

Are people actually visiting the podcast website after seeing my posts?

This is why UTM tracking is so useful for content creators, marketers, and businesses.

Do UTM Parameters Track Personal Information?

Not inherently.

A parameter like:

utm_source=chatgpt.com

doesn't reveal your name, email address, or what you asked ChatGPT.

It simply contains a label identifying the declared source.

However, there's an important privacy consideration.

Website owners can combine UTM parameters with other analytics information, including cookies, session identifiers, and on-site activity.

That means UTM data can become part of a larger tracking system.

It's also worth remembering that query strings can appear in browser history, server logs, and shared URLs.

For that reason, developers should avoid putting sensitive information such as email addresses, passwords, or personal identifiers into UTM parameters.

Should Developers Care About UTM Parameters?

I think so.

As developers, we spend a lot of time building applications, improving performance, and making sure everything works correctly.

But understanding how users discover those applications is important too.

If you're building a product, maintaining a blog, running a newsletter, or promoting an open-source project, UTM parameters can help you measure where your audience comes from.

There's also the growing role of AI assistants in content discovery.

If someone finds your project through ChatGPT, Claude, or another AI tool, you probably want to know that.

UTM parameters and referral analytics can help, although neither gives you a complete picture of all AI-driven discovery.

One practical tip: use UTM parameters mainly for links shared outside your own website. Adding campaign tags to internal navigation links can distort acquisition reporting by replacing the original campaign attribution.

And keep your naming consistent. For example, LinkedIn and linkedin may appear as different values in analytics reports.

Final Thoughts

UTM parameters might look like random characters at the end of a URL, but they serve a useful purpose.

They help connect a website visit to the link or campaign that brought someone there.

What I find particularly interesting is how this applies to AI assistants.

We're increasingly discovering content through conversations with AI, not just traditional search engines or social media.

And those little parameters at the end of a URL are one of the ways website owners can understand that shift.

So, the next time you click a link and notice utm_source=chatgpt.com, you'll know what it's doing.

It's simply a clue about where that visit came from.

Further reading