If you've ever clicked a link from an email newsletter or an ad and noticed the URL suddenly looks like example.com/page?utm_source=newsletter&utm_medium=email&utm_campaign=july_sale, you've met UTM parameters. They're everywhere, and they exist for a specific reason.

What UTMs actually do

UTM stands for Urchin Tracking Module, named after Urchin Software Corporation, which Google acquired in 2005 and turned into Google Analytics. The parameters are tags a marketer appends to a URL so that analytics tools can attribute the visit to a specific campaign, channel, or piece of creative.

The five standard UTM parameters are:

• utm_source — where the click came from (e.g. newsletter, twitter).
• utm_medium — the type of channel (email, cpc, social).
• utm_campaign — the specific campaign (july_sale).
• utm_term — used for paid keywords.
• utm_content — differentiates two versions of the same ad or link.

Do they change the page you land on?

Almost never. UTM parameters are read by analytics scripts, not by the page's server. Removing them takes you to the same page. That's why they're safe to strip when you're saving, bookmarking, or sharing a link.

Why bother cleaning them?

• Cleaner sharing. A short URL looks trustworthy; a URL with six UTMs looks like spam.
• Better deduplication. Two links to the same article with different UTMs will look "different" to any script that compares strings.
• Privacy hygiene. UTMs can leak the sender or the campaign you clicked, which you may not want stored in your notes or shared with a friend.

Other tags in the same family

A few more parameters do a similar job for other ad platforms:gclid (Google Ads), fbclid (Facebook), msclkid (Microsoft Ads),mc_cid and mc_eid (Mailchimp), yclid (Yandex), and many others. SlinkyLinky strips all of these by default.