I Built a Free UTM Link Inspector to Catch Campaign Tracking Mistakes

Campaign tracking mistakes are easy to overlook.

You create a URL for a newsletter, social media post, or advertising campaign. Everything looks fine at first. But somewhere along the way, a parameter gets misspelled, a required value is left empty, or the same UTM parameter appears twice.

The URL might still open the correct page, which makes these mistakes harder to notice.

While working on SaaSCostLab, I wanted a simple way to inspect these links before using them in campaigns. That led me to build a small, browser-based UTM Link Inspector.

The problem I wanted to solve

Consider this URL:

https://example.com/pricing?utm_source=linkedin&utm_source=google&utm_medium=&utm_campaing=launch#plans

It looks like an ordinary campaign link, but there are several issues:

• utm_source appears twice, with different values.
• utm_medium exists but has an empty value.
• utm_campaign is missing because it was accidentally written as utm_campaing.

A browser can still recognize the URL structure. That doesn't mean the tracking information is correct.

When people manage multiple campaigns, especially through spreadsheets or shared documents, these small inconsistencies can become difficult to spot manually.

What I built

The UTM Link Inspector accepts a complete campaign URL and checks the tracking parameters in it.

It currently does a few things:

1. Checks required UTM parameters

It looks for utm_source, utm_medium, and utm_campaign and identifies values that are missing or empty.

2. Finds duplicate parameters

If the same standard UTM parameter appears multiple times, the inspector flags it instead of silently treating the URL as clean.

This is particularly useful when someone adds new campaign parameters to a link that already contains tracking information.

3. Flags unfamiliar UTM-like keys

A typo such as utm_campaing can be easy to miss in a long URL. The inspector highlights unfamiliar UTM-like parameter names so they can be reviewed.

4. Shows a duplicate-safe preview

For repeated standard UTM parameters, the preview keeps the first non-empty value. It's meant to help with review, not to silently modify the original destination.

Why I kept the inspection in the browser

I didn't want checking a campaign URL to require sending that URL to another server.

The inspector uses the browser's URL parsing capabilities. The destination isn't fetched, and the inspection itself doesn't create a redirect or save a history of the link.

There's also no account required.

There is an important limitation here: checking a URL's syntax doesn't prove that the destination works, that GA4 will attribute the traffic correctly, or that a particular advertising platform will interpret the parameters as intended.

The tool checks the structure of the tracking link. It doesn't pretend to validate the entire analytics setup.

Try it with your own campaign URL

I made the inspector available as one of the free utilities on SaaSCostLab:

Try the UTM Link Inspector

You can also paste the example URL from earlier in this post and see what gets flagged.

The goal is straightforward: help catch avoidable tracking mistakes before links are copied into campaigns.

What I'd like to improve

This is an early version, and I'm interested in hearing from developers and marketers who work with campaign URLs regularly.

I'm particularly curious about how other people handle:

• UTM parameters added by multiple tools.
• Inconsistent naming conventions across marketing teams.
• Campaign URLs that contain both tracking and unrelated query parameters.
• Duplicate values introduced during URL generation.

If you've worked on tracking systems or campaign automation, what are the most annoying UTM edge cases you've encountered?

I'd be interested to hear what this inspector misses or gets wrong. That's the kind of feedback that would be useful for improving it.