Guide · Updated 2026-10-08
UTM Tags: A Naming Guide That Keeps Google Analytics Clean
How UTM parameters work, why capital letters and spaces split your reports, and a simple naming convention to follow when you build campaign links.
UTM tags are short pieces of text added to a link so analytics can tell where a visit came from. They are powerful and easy to get wrong. The most common problem is inconsistent spelling, which splits one campaign into several rows in your reports. This guide shows a convention that avoids that, using the UTM Link Builder and the UTM Link Auditor.
The five parameters
| Parameter | Question it answers | Example |
|---|---|---|
| utm_source | Where did the visitor come from? | newsletter |
| utm_medium | What kind of channel was it? | |
| utm_campaign | Which campaign? | spring-sale |
| utm_term | Which keyword (paid search)? | running-shoes |
| utm_content | Which version of the link? | header-button |
Source, medium and campaign are the ones to always fill in. Built with those values, a link looks like https://example.com/offer?utm_source=newsletter&utm_medium=email&utm_campaign=spring-sale.
Why consistency matters
Analytics treats text exactly as written. Facebook and facebook are two sources, and paid social and paid-social are two mediums. In the audit of four sample links, those spellings were flagged as the same thing written differently, along with Autumn_Sale and autumn-sale. If you do not fix this at the link stage, you have to merge rows in every report later.
A simple convention
- Lower case only. The builder does not change your capitals, so type them in lower case.
- Hyphens, not spaces or underscores. A space becomes a plus sign in the link, which is easy to misread.
- Use a fixed list for source and medium, such as email, social, cpc, referral, and stick to it.
- Campaign names that sort: a short name plus a month or year, such as spring-sale-2026.
- No personal data in any value, because links can be shared and logged.
Links that already have parameters
The builder keeps existing parameters and any #section at the end. A link such as example.com/offer?x=1#top with source, medium and campaign added becomes ...?x=1&utm_source=...&utm_medium=...&utm_campaign=...#top. The address must start with https:// or http://.
Auditing the links you already have
If you have a list of campaign links, paste it into the audit tool. It flags missing utm_source, utm_medium or utm_campaign, capital letters, spaces, repeated parameters and duplicate links, and it offers a cleaned list in lower case with one separator.
When not to use UTMs
- On links between pages of your own site, because they can overwrite the real traffic source.
- On links where the destination needs a clean address, such as pages shared by search engines.
Frequently asked questions
Are UTM values case sensitive? Yes, in Google Analytics, so keep everything lower case.
Do I need utm_term and utm_content? Only if you want to tell keywords or link versions apart.