What are UTM parameters?
UTM parameters are tags on the end of a link, like ?utm_source=instagram&utm_medium=social. They don't change the page. They tell your analytics tool where the visitor came from.
Without them, a lot of visits land as direct or unassigned traffic. Apps like Instagram and TikTok open links in their own in-app browsers, which often don't pass on where the click came from. UTM tags fix that by carrying the answer inside the link.
Naming rules that keep reports clean
UTM values are case-sensitive in GA4, so Instagram, instagram and IG show up as three different sources. Pick one style and stick to it:
- Use lowercase for everything.
- Use underscores or hyphens instead of spaces.
- Use source for the platform (instagram, tiktok, newsletter) and medium for the type of channel (social, email, cpc).
- Use content to tell apart links in the same place, like shop_button and newsletter_button.
- Keep a shared sheet of the names you use, so everyone on the team tags links the same way.
Which medium to use
GA4 sorts visits into default channels partly by medium. It puts a visit in Email when the source or medium is email, and in Organic Social when the medium is social or the source is a known social site. Paid channels need a medium like cpc or paid.
Use a medium GA4 doesn't recognise and the visit lands in Unassigned. That's normal for offline sources like flyers with a QR code: find them in your reports by source and medium instead of by channel.
Mistakes to avoid
A few habits quietly ruin campaign data:
- Tagging links between pages on your own site. It overwrites where the visit really came from.
- Putting personal details like email addresses in UTM values. They end up in your analytics reports.
- Using one tagged link everywhere. Make one per place, or the numbers can't tell you anything.
Frequently asked questions
Which UTM parameters do I need?
Always add source, medium and campaign. GA4 uses source and medium to decide the channel, and campaign groups your links. Term and content are optional.
Are UTM values case sensitive?
Yes. GA4 treats Instagram and instagram as two different sources, which is why this builder lowercases values by default.
Where do I see UTM data in GA4?
Go to Reports, then Acquisition, then Traffic acquisition. Change the table's main column to Session source / medium or Session campaign.
Do UTM tags hurt SEO?
Not on links you share elsewhere. Avoid them on links between your own pages, and give each page a canonical tag so tagged copies of a URL aren't treated as separate pages.
Can I use UTM links on Instagram and TikTok?
Yes. Use them in your bio link, stories and ads. The tags travel with the click, so your analytics sees the source even when the app's browser hides it.