What is UTM parameters?
UTM parameters are query-string tags — utm_source, utm_medium, utm_campaign, utm_term, utm_content — added to a link so analytics can attribute the click to a campaign. They carry no personal data and require no cookie. Everything they report is whatever you typed when you built the link, so their accuracy is entirely a discipline problem.
The five parameters
| Parameter | Answers | Example |
|---|---|---|
utm_source | Which site or product | newsletter, x, partner-blog |
utm_medium | Which kind of channel | email, cpc, social, referral |
utm_campaign | Which campaign | spring-launch |
utm_term | Which keyword (paid search) | privacy+analytics |
utm_content | Which variant or placement | header-cta, variant-b |
Source and medium are the two that matter. The rest add resolution once the first two are consistent.
The discipline problem
UTM values are case-sensitive and free text, so Email, email and e-mail become three separate channels in every report you run afterwards. There is no cleanup that fixes historical data reliably.
A convention worth adopting on day one:
- Lowercase everything, always.
- Hyphens, never spaces or underscores.
- A fixed vocabulary for
utm_medium— pick five values and never invent a sixth. - Write it down where whoever builds links can find it.
Our UTM builder applies these rules as you type, which is cheaper than agreeing on them and then not following them.
What not to do
- Never tag internal links. A UTM on a link between two of your own pages restarts attribution mid-visit and credits the sale to your own homepage.
- Never put personal data in a UTM. It ends up in analytics, in logs, in shared reports and in referrer headers on the next hop.
- Do not rely on them for organic traffic. You cannot tag a link someone else wrote about you. That is what the referrer is for, and why both matter.